work out the value of x

Answer:
x=128
Step-by-step explanation:
first find the base angles (isosceles triangles have congruent base angles and two congruent legs) so do 180-76=104 then divide by 2 =52. Then to find exterior angle add the top angle (76) to one base angle (52) then you get 128 which is the exterior angle.
*Any questions just ask*