Answer:
c. 71°
Step-by-step explanation:
You have isosceles triangle XYZ with a.pex angle Y = 38°. You want to know the measure of angle Z.
Angle sum theorem
The base angles of the triangle are X and Z, which are congruent. The sum of all angles is 180°:
X +Y +Z = 180°
2Z +38° = 180° . . . . . . substitute for X and Y
2Z = 142° . . . . . . . . . subtract 38°
Z = 71° . . . . . . . . . . divide by 2
The measure of angle Z is 71°.
