Find an expression for the measure of ∠5 (in degrees) if m∠3 = (6x)°

Question

Consider the following isosceles triangle. Note the use of dashes on congruent sides of the triangle.

Find an expression for the measure of ∠5 (in degrees) if m∠3 = (6x)° and the line segments shown bisect the angles of the isosceles triangle. Use arithmetic or algebra, as needed.

Answer 1

angle 3 = 6x

angle 1 = 180-12x

(1/2) of angle 3 = 3x

(1/2) of angle 1 = 90-6x

angle 5 = 180-(3x+90-6x) = 90 + 3x