Answer:
Step-by-step explanation:
Properties of an Isosceles Triangle
(Most of this can be found in Chapter 1 of B&B.)
Definition: A triangle is isosceles if two if its sides are equal.
We want to prove the following properties of isosceles triangles.
Theorem: Let ABC be an isosceles triangle with AB = AC. Let M denote the midpoint of BC (i.e., M is the point on BC for which MB = MC). Then
a) Triangle ABM is congruent to triangle ACM.
b) Angle ABC = Angle ACB (base angles are equal)
c) Angle AMB = Angle AMC = right angle.
d) Angle BAM = angle CAM
Corollary: Consequently, from these facts and the definitions:
Ray AM is the angle bisector of angle BAC.
Line AM is the altitude of triangle ABC through A.
Line AM is the perpendicular bisector of B
Segment AM is the median of triangle ABC through A.
Proof #1 of Theorem (after B&B)
Let the angle bisector of BAC intersect segment BC at point D.
Since ray AD is the angle bisector, angle BAD = angle CAD.
The segment AD = AD = itself.
Also, AB = AC since the triangle is isosceles.
Thus, triangle BAD is congruent to CAD by SAS (side-angle-side).
This means that triangle BAD = triangle CAD, and corresponding sides and angles are equal, namely:
DB = DC,
angle ABD = angle ACD,
angle ADB = angle ADC.
(Proof of a). Since DB = DC, this means D = M by definition of the midpoint. Thus triangle ABM = triangle ACM.
(Proof of b) Since angle ABD = angle ABC (same angle) and also angle ACD = angle ACB, this implies angle ABC = angle ACB.
(Proof of c) From congruence of triangles, angle AMB = angle AMC. But by addition of angles, angle AMB + angle AMC = straight angle = 180 degrees. Thus 2 angle AMB = straight angle and angle AMB = right angle.
(Proof of d) Since D = M, the congruence angle BAM = angle CAM follows from the definition of D. (These are also corresponding angles in congruent triangles ABM and ACM.)
QED*
*Note: There is one point of this proof that needs a more careful “protractor axiom”. When we constructed the angle bisector of BAC, we assumed that this ray intersects segment BC. This can’t be quite deduced from the B&B form of the axioms. One of the axioms needs a little strengthening.
The other statements are immediate consequence of these relations and the definitions of angle bisector, altitude, perpendicular bisector, and median. (Look them up!)
Definition: We will call the special line AM the line of symmetry of the isosceles triangle. Thus we can construct AM as the line through A and the midpoint, or the angle bisector, or altitude or perpendicular bisector of BC. Shortly we will give a general definition of line of symmetry that applies to many kinds of figure.
Proof #2 (This is a slick use of SAS, not presented Monday. We may discuss in class Wednesday.)
The hypothesis of the theorem is that AB = AC. Also, AC = AB (!) and angle BAC = angle CAB (same angle). Thus triangle BAC is congruent to triangle BAC by SAS.
The corresponding angles and sides are equal, so the base angle ABC = angle ACB.
Let M be the midpoint of BC. By definition of midpoint, MB = MC. Also the equality of base angles gives angle ABM = angle ABC = angle ACB = angle ACM. Since we already are given BA = CA, this means that triangle ABM = triangle ACM by SAS.
From these congruent triangles then we conclude as before:
Angle BAM = angle CAM (so ray AM is the bisector of angle BAC)
Angle AMB = angle AMC = right angle (so line MA is the perpendicular bisector of BC and also the altitude of ABC through A)
QED
Faulty Proof #3. Can you find the hole in this proof?)
In triangle ABC, AB = AC. Let M be the midpoint and MA be the perpendicular bisector of BC.
Then angle BMA = angle CMA = right angle, since MA is perpendicular bisector.
MB = MC by definition of midpoint. (M is midpoint since MA is perpendicular bisector.)
AM = AM (self).
So triangle AMB = triangle AMC by SAS.
Then the other equal angles ABC = ACB and angle BAM = angle CAM follow from corresponding parts of congruent triangles. And the rest is as before.
QED??
Yes, This statement is valid.
What is mean by Triangle?A triangle is a three sided polygon, which has three vertices and three angles which has the sum 180 degrees.
Given that;
The two sides of a triangle are congruent.
Then, In ΔABC;
⇒ AB ≅ BC
So, ΔABC is isosceles.
Now,
Since, The two sides of a triangle are congruent.
We know that;
In a triangle if two sides are equal then it is an Isosceles triangle.
So, The given statement '' ΔABC is isosceles'' is valid.
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Simplify the fraction 2.5/18
Answer:
1/7.2
Step-by-step explanation:
if you divide the numerator and denominator by 2.5, you have one as the numerator and 7.2 as the denominator.
Solve for x.
x + 15
9
X =
1. If two lines intersect at a point, then the vertically opposite angles are
Answer:
Congruent
Step-by-step explanation:
They are the same because they are vertical angles.
-Chetan K
please someone help me. Im giving brainliest!!
Answer:
False
Step-by-step explanation:
You'll add 10 to both sides. you'll end up with
2x =24.
Now, you divide 2 on both sides.
x=12
At target, they have 4 DVDs for $36. What is the constant of proportionality that relates the cost of DVDs, y, to the number of DVDs bought, x?
Answer:
Step-by-step explanation:
Cost of 4 DVDs = $36
Cost of 1 DVD = 36÷ 4 = $9
Cost of x DVD = 9 *x = 9x
y = 9x
Use properties of exponents to solve for a and b in the problem below. No calculator allowed. Please help; I don't know what I'm doing.
hmmmmmmmmmmmmmmmmmmmmmmmmmmm
Answer:
Step-by-step explanation:
1st, 3rd, and 6
PLEASE HELPPPPP
Write an equation to represent the total number of words, y, that Mrs. Garcia can type in x minutes. __________
If Mrs. Garcia maintains a constant speed consistent with the results above, how many words will she type in 49 minutes?___________
Answer:
3,430
Step-by-step explanation:
because if you multiply 49 x70 you get the answer
Answer:
a) y = x*70
b) 3430 words
Step-by-step explanation:
b) y = x*70
y = 49*70
y = 3430
Can someone plss help me with this!!
QUESTION: How do we communicate to a computer of what to put on a web page?
Answer:
you just type it in u can't talk to a computer
October 2021 to Present
1 hours per week [ ?] weeks per year
What is the value of 2x(3+x/2) when x=−2?
Answer:
-8
Step-by-step explanation:
[tex]2x(3+\frac{x}{2})[/tex] [tex]2*(-2)(3+\frac{(-2)}{2})[/tex] [tex]-4(3+(-1))[/tex] [tex]-4(2)[/tex] [tex]-8[/tex]if a =5 b =6 and c=a-2 . answer the question , 8a-2b+1c
Answer:
here given.,
a =5 b =6 and c=a-2(5-2=3)
putting the given value in the equation...we get..
=8*5-2*6+1*3
=40-12+3
=43-12
=31
someone answer this please
Answer:
Neither
Step-by-step explanation:
A = (-2,-5) and B = (4,7)
Slope = (7 - - 5)/(4 - - 2)
= 12/ 6 = 2
Slope = 2
C = (0,2) and D = (8,2)
Slope = (2 - 2) / 8 - 0)
= 0 / 8 = 0
Slope = 0
There are two integers that combine to -19 and their product is 70. Find the two integers, then the SMALLER integer is your answer for this question?
Answer:
-14
Step-by-step explanation:
a + b = -19
(a)(b) = 70
To solve this problem, isolate one variable in one of the two equations and then substitute it in.
So, a + b = -19
-> a = -19 - b
b(-19 - b) = 70
Distribute.
-19b - b^2 = 70
Move all to one side.
b^2 + 19b + 70 = 0
Factor. Find two numbers that multiply to 70, but add to 19.
(b + 5) (b + 14) = 0
Zero product rule.
b = -5, b = -14
Now, substitute the two answers for b back into the original equation for a.
a - 14 = -19
a = -5
a - 5 = -19
a = -14
So, the answers are b = -5, b = -14, a = -5, a = -14. Since you said that the smallest integer is the answer, the answer is -14.
Lucy runs 6 miles in 50 minutes. At the same rate, how many miles would she run in 35 minutes?
In a class of 52 students, 16 are science students. If I/3 of the boys and 1/4 of the girls are science students, how many boys are in the class?
Answer:
36
Step-by-step explanation:
x = # of boys, y = # of girls
x/3+y/4=16; mult. ea side by 12: 4x+3y=192 (1)
x+y=52; mult. ea side by 3: 3x+3y=156 (2)
(1)-(2)=x=36
Is the relation below a function? If it is a function, state its domain. (0, 3) , (2, -3) , (1, 8) ,(2, 3)
A. The relation is not a function.
B. The relation is a function. The domain is {0 , 1, 2}
C. The relation is a function. The domain is {-3 , 3, 8}
D. The relation is a function. The domain is {-3, 0, 1, 2, 3, 8}
The relation (0, 3) , (2, -3) , (1, 8) ,(2, 3) is a function. The domain is {0 , 1, 2}; Choice B
Definition:
A relation can only be termed a function if it relates each element in its domain to only one element in the range.In essence, When the graph of a function is plotted, a vertical line will intersect it at only one pointThe domain or set of departure of a function is the set into which all of the input of the function is constrained to fall.Read more:
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m2-n2 factorization plz
Answer:
(m+n)(m-n)
Step-by-step explanation:
formula: x^2 - y^2 = (x+y)(x-y)
add m and n to x and y to get
m^2 - n^2
then the formula says insert the m and n into the formula answer of (x+y)(x-y) to get our answer of
(m+n)(m-n)
43. Ozzie Foster deposits $2,000 at the end of each year (Ordinary annuity) into an Individ-
ual Retirement Account at Boise Bank. The account pays 7% compounded annually. (a)
How much will be in the account in 25 years? (b) If Ozzie had deposited the $2,000 at the
beginning of each year (Annuity due), how much would be in the account in 25 years?
Answer:8349y
Step-by-step explanation:
Triangle ABC is congruent to triangle DEF. Angle B is a right angle, and m∠C = 42°. What is m∠D?
Answer:
Step-by-step explanation: Triangle ABC is congruent to triangle DEF. Angle B is a right angle, and m∠C = 57°. What is m∠D? can someone help plsss
If Triangle ABC is congruent to triangle DEF then measure of angle D is 48 degrees.
Given, Triangle ABC is congruent to triangle DEF.
Angle sum property of triangle: Sum of all the interior angles of the triangle is 180 degrees.
Congruent triangles: When two triangles are congruent they are similar in shape and coincide when superimposed.
Now in triangle ABC,
∠B = 90°
∠C = 42°
Apply angle sum property,
∠A + ∠B + ∠C = 180 degrees
∠A + 90° + 42° = 180°
∠A = 48°
When Triangle ABC is congruent to triangle DEF,
∠A = ∠D
∠B = ∠E
∠C = ∠F
Thus measure of angle D is equal to measure of angle A.
∴∠A = ∠D = 48°
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Ana was given $180 for her birthday,
She spent 1/3
of her money on a helmet:
13/20
of her money on a skateboard
The rest was spent on stickers
She spent
.
How much did Ana spend on stickers?
Answer: 3
Step-by-step explanation:
180 / 1/3 = 60
180 / 13/20 = 117
117 + 60 = 177
180 - 177 = 3
Juwan is throwing a birthday party for his son. He originally ordered 3 pizzas, but he realizes that his son invited more people than he thought, so he decides to order at least 1 more pizza for every 4 people that come to the party. The total number of pizzas, y, can be expressed in terms of the number of people that show up to the party, x. Which inequality represents this situation?
1.
[tex]y \geqslant - \frac{1}{4} x + 3[/tex]
2.
[tex]y \geqslant \frac{1}{4} x + 3[/tex]
3.
[tex]y \leqslant 4x - 3[/tex]
4.
[tex]y \leqslant 4x + 3[/tex]
Answer:
b.
Step-by-step explanation:
If there are 45 students in a classroom, of which 52% are women under 18 years of age. Please indicate:
a. How many male students are there in the class?
b. Is it possible to say that most of the students are minors?
Answer:
A. 22
b. Yes. Because there are 23 woman and they are all under 18 and there are 22 males. In which we don't know if they are underage, but it doesn't really matter because there is one more girl in the room than boys. And all woman are underage so there for there are more underage students in the room.
Step-by-step explanation:
Hope this helps :)
Pls make brainliest :p
And have an amazing day <3
Answer:
there would be 21.6 males. That doesn't work, so you'd have 21 or 22(probably 22)
yes, most of the students are minors. 52% percent at least are under 18 years. 52% is more than half, so that would make it so most are minors.
Step-by-step explanation:
By which rule are these triangles congruent?
A)
AAS
B)
ASA
SAS
D)
SSS
Answer:
i think
these triangles are congruent by the rule of AAS
An absolute value function can be written as a piecewise function always, sometimes, or never? Your answer should demonstrate an understanding of both types of functions. Explain your answer using complete sentences.
Hello,
Let us choose an element x of the Real Numbers. So x can either be positive or negative. So we have two case to study :
Case 1 : x is positive.
If x is positive, that is, x = 0, 1, 2, 3, ....
then the absolute value gives us the same number : |0| = 0
|1| = 1
|2|= 2
etc.
so the absolute value of x positive equals x : |x| = x
Case 2 : x is negative.
If x is negative, that is, x = - 1, - 2, -3, .....
then the absolue value gives us the opposite value : |-1| = - (-1) = 1
|-2| = -(-2) = 2
|-3| = -(-3) = 3
(Remember the product of two negative sign is a positive signe : -1 * -1 = +1)
And so we can join both cases as a piecewise function, writing :
|x| = [tex]\left \{ {{x=x if x\geq 0 } \atop {x= - x if x<0 }} \right.[/tex]
so x = x if x ≥ 0 and x = - x if x < 0
Finally the answer is : it depend on the function itself. If the function takes both positive and negative value, then the absolute value of the function will be written as a piecewise function. If the function takes only positive or negative value, then it won't be written as a piecewise function.
if anyone can help me that would be great
30+[10+(3²-4)]
30+[10+(9-4)]
30+[10+5]
30+15
45
graph the inequality B is greater than -3
A box weighs 90 grams write down in terms of b the weight of b boxes
PLEASE HELP!! DUE IN 1 HOUR!!
Answer:
b
Step-by-step explanation:becuse if you addd its b
May I please receive help?