Question

One angle in an obtuse isosceles triangle measures 40°. What are the measures of the other two angles?

Answer 1

40° and 100

Explanation:

An obtuse triangle has one obtuse angle, or an angle that measures more than 90° but less than 180°. Options 1 and 2 are not correct, because these are acute angles.

So, one of the angles must be 40°, and the other may be 100° or 120°.

The measures of the angles in a triangle add up to 180°.

The other two angles are 40° and 100°.

Answer 2

"In an isosceles triangle two angles are the same and the third is different. However, the angles in the triangle must add up to 180. If the 100 degree angle was one of the 2 identical angles, then the angles in the triangle would add up to more than 200. Because of this the 100 degree angle must be the different angle."