Question

Find angle B if triangle ABC below is isosceles. 

A: 77 Degrees 
B: 36 Degrees 
C: 50 Degrees 
D: 44 Degrees

Answer 1

Use the Isosceles Triangle Theorems. The Base Angles Theorem. If two sides of a triangle are congruent, then the angles opposite those sides are congruent. Converse of the Base Angles Theorem. So, X + 8 = 2X - 20
subtract x from both sides -X -X
new equation 8 = X - 20
add 20 to both sides +20 +20
28 = X
Angle B = X + 8
sub 28 for X (28 + 8 = 36)

Answer 2

so these will equal each other so put them to equal to find x
2x-20=x+8
+20 +20
2x=x+28
-x -x
x=28 now plug it in
2(28)-20= 36
(28)+8= 36, since they're equal this make it an isosolece and it's correct
So the answer is B. hope this helped you have a great day!!