Question

In trapezoid ABCD, find m∠A if m∠B= 25°, m∠C = 155° and m∠ D= 117°.

A) 25°
B) 63°
C) 73°
D) 92°

Answer 1

D 92 is the answer..........

Answer 2

We know that a trapezoid is a quadrilateral and we also know that the sum of the four interior angles of a quadrilateral always equals
`360^(\circ)`.

Now, it is given that 3 interior angles of a trapezoid are m∠B= 25°, m∠C = 155° and m∠ D= 117°. The sum of these three angles is:

25°+155° +117°=
`297^(\circ)`

Thus, the measure of the fourth interior angle,
`m\angle A` will be:

`m\angle A` =
`360^(\circ)-297^(\circ)=63^(\circ)`

Thus, out of the given options, Option B is the correct one.