Question

C --- (a) D 1200 90° 90° A B.​

Answer 1

$answer$

We know, by angle sum property, the sum of angles of a quadrilateral is 360o.

The given angles are, 75o,90o,75o.

Let the fourth angle be xo.

Then, 75o+90o+75o+xo=360o.

⇒ 360o−(75o+90o+75o)=x∘

⇒ xo=360o−240o=120∘.

Therefore, the fourth angle is xo=120o.