If m∠X= 63, what is m∠YWZ?
A.27
B.90
C.17
D. 63

Solution:
we are given with an isosceles triangle in the diagram , in which m∠X= 63.
we have been asked to find m∠YWZ?
Since the given triangle is an isosceles triangle and wx=wz so their corresponding angles will be equal so we can write
m∠X= 63=m∠Z= 63
Since the sum of the angles in a Triangle is 180 degree, So we can write
m∠W=180-63- 63=54
Since the line through the vertex W is dividing the angle W so we can write
[tex] m<YWZ=\frac{1}{2}<W \\
\\
m<YWZ=\frac{1}{2}*54 \\
\\
m<YWZ=27 \\
[/tex]
Hence the correct option is A.