Question

In the given isosceles triangle, find angle M if it is given that sides MN and MO have equal lengths.

• A. ${110}^o$
• B. ${70}^o$
• C. ${80}^o$
• D. ${120}^o$

Answer 1

The correct option is A ${110}^o$

Angle sum property: The sum of the three interior angles of a triangle is 180°.

Given,
MNO is an isosceles triangle. Therefore, angles N and O are equal.

m∠N = 35° and m∠O = 35°

In triangle ABC,
m∠N = 35°
m∠O = 35°

So,
m∠M + m∠N + m∠O = 180°

∴ m∠N + m∠O = 35° + 35° = 70°

Third angle = 180° - 70°
= 110°

∴ m∠M = 110°