Find the measure of angle B in isosceles triangle ABC.
Responses
A 85°85°
B 65°65°
C 55°55°
D 40°
Insufficient information provided. Isosceles triangle ABC could have a variety of angles and side lengths, so the measure of angle B cannot be determined without further information.
In an isosceles triangle, the base angles (angles opposite the equal sides) are congruent.
Let's denote angle A as the vertex angle and angles B and C as the base angles.
Because it is an isosceles triangle, the base angles B and C are congruent.
Therefore, the measure of angle B is equal to the measure of angle C.
Thus, the measure of angle B is 55°.
Therefore, the answer is C) 55°.