Question

The three angles of a quadrilateral are ${75}^{\circ }$, ${90}^{\circ }$ and ${75}^{\circ }$. The quadrilateral is a parallelogram.

• A. 90°
• B. 120°

Answer 1

The correct option is B

120°

Sum of all angles of a quadrilateral is ${360}^{\circ }$.

Fourth angle = ${360}^{\circ }$-(${75}^{\circ }$+${90}^{\circ }$+${75}^{\circ }$)

=${120}^{\circ }$
We know that the opposite angles of a parallelogram are equal, this quadrilateral is not a parallelogram since it has three different angles and only one pair of equal angles.