Select all that apply.In an isosceles triangle, one angle measures 20°. What are the measures of the other two angles?80° and 80°90° and 90°20° and 140°20° and 60°

All of a triangles angles add up to 180, this is known as the triangle sum conjecture.


an Iscoceles triangle is a triangle that has two or more congruent sides.

if a triangle is Iscoceles then th e two angles that are made by the congruent sides and base are also congruent.

if you know that one of the angles is 20 that. The sum of the other two angles must be 160.

That means that answer 2 and 4 are incorrect.

Answers 1 and 3 both have a total angle sum of 160. since this is true the correct answer depends on where the known angle is. If it is the angle that is formed by the two congruent sides than the answer is number one. but if it is formed by one of the congruent sides and the base then the answer is number 3.