Which best explains whether or not all isosceles triangles are similar? all isosceles triangles are similar. two angles within each triangle are always congruent. all isosceles triangles are similar. the triangle sum theorem states that the sum of the angles in a triangle is 180°. therefore, the third angle can always be determined. all isosceles triangles are not similar. the pair of congruent angles within one triangle is not necessarily congruent to the pair of congruent angles within the other triangle. all isosceles triangles are not similar. given only the vertex angle of an isosceles triangle, there is not enough information to determine the measures of the base angles. therefore, it is not possible to determine if the base angles of one isosceles triangle are congruent to the base angles of another.

Answer

All isosceles triangles are not similar. The pair of congruent angles within one triangle is not necessarily congruent to the pair of congruent angles within the other triangle.

Explanation

An isosceles triangle is a triangle whose any two sides are equal. Two angles in an isosceles triangles are also equal. The isosceles triangle can be similar if and only if the sides are proportional. This can conclude that isosceles triangles are not always similar.

From the choices given in the question, the appropriate answer would be,

All isosceles triangles are not similar. The pair of congruent angles within one triangle is not necessarily congruent to the pair of congruent angles within the other triangle.

Step-by-step explanation:

The correct answer is C All isosceles triangles are not similar. The pair of congruent angles within one triangle is not necessarily congruent to the pair of congruent angles within the other triangle.