Answer:
7. 69° 8. 118°
Step-by-step explanation:
to know
- isosceles triangles have the base angles congruent
- the sum of angles in a triangle is 180
180 -42 = 138 sum of the two base angles
138 /2 = 69 is one base angle
31*2 = 62 are the 2 base angles
180 -62 = 118° vertex angle
