In the given figure, ΔABC is an equilateral triangle. Find m∠BEC.
It is given that, Δ ABC is an equilateral triangle
We have to find `m angle BEC`
Since Δ ABC is an equilateral triangle.
So `angle A + angle B + angle C = 180°`
`angle A = angleB = angleC` = 60° …… (1)
Since, quadrilateral BACE is a cyclic qualdrilateral
So , `angle A + angleE = 180°` (Sum of opposite angles of cyclic quadrilateral is 180° .)
`60° + angle E = 180°`
`angle E = 120°`
`m angle BEC = 120°`