Both the side are 21 units. ⇒ It is an isosceles triangle.
---------------------------------------------------- Property of the angles in a triangle: ---------------------------------------------------- Sum of all angles in a triangle = 180°
---------------------------------------------------- Find x: ---------------------------------------------------- x + x + 38 = 180
---------------------------------------------------- Combine like terms: ---------------------------------------------------- 2x + 38 = 180
---------------------------------------------------- Take away 38 from both sides: ---------------------------------------------------- 2x = 142
---------------------------------------------------- Divide by 2 on both sides: ---------------------------------------------------- x = 71
---------------------------------------------------- Answer: x = 71° ----------------------------------------------------
