77.6k views
16 votes
In ΔSIM, if IS=IM and ∠S = 78°, what is the exact measure of ∠M?

A. 180°
B. 24°
C. 80°
D. 78°

2 Answers

5 votes

Answer:

D

Explanation:

since IS = IM then Δ SIM is isosceles with the 2 base angles being congruent , then

∠ M = ∠ S = 78°

User Reno Jones
by
7.3k points
6 votes

Answer:

D. 78°

Explanation:

In the given isosceles triangle, the congruent base angles are ∠S and ∠M. If the measure of angle S is 78°, then the measure of angle M is 78°.

In ΔSIM, if IS=IM and ∠S = 78°, what is the exact measure of ∠M? A. 180° B. 24° C-example-1
User MatCarey
by
7.1k points