Base angles of isosceles triangle are the same, Angle UVW = Angle UWV let x= Angle UVW = Angle UWV Sum of interior angles of a triangle sums up to 180∘ 70∘+x0+x∘=180∘ 70+2x=180 2x=180−70 2x=110 Divide both sides of the equation by 2 2x∕2=110∕2 x=55