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 [tex] 360^{\circ} [/tex].
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°=[tex] 297^{\circ} [/tex]
Thus, the measure of the fourth interior angle, [tex] m\angle A [/tex] will be:
[tex] m\angle A [/tex] = [tex] 360^{\circ}-297^{\circ}=63^{\circ} [/tex]
Thus, out of the given options, Option B is the correct one.
