Question

find the value of unknown angle x in isosceles triangle​

Answer 1

x = y (Angles opposite to equal sides)

But x + y + 80° = 180° (Angles of a triangle)

⇒ x + x + 80° = 180°

⇒ 2x = 180° - 80° = 100°

⇒ x = 100°/2 = 50° ∴ y = x = 50°

Hence x = 50°, y = 50°