Question

The three angles of a quadrilateral are ${85}^{\circ }$, ${90}^{\circ }$ and ${85}^{\circ }$. The quadrilateral can be -

• A. 90°
• B. 120°
• C. Trapezium
• D. None of the above

Answer 1

The correct option is D

None of the above

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

So, fourth angle $={360}^{\circ }-({85}^{\circ }+{90}^{\circ }+{85}^{\circ })={100}^{\circ }$

Since the pairs of opposite angles of a parallelogram and rhombus are equal, this quadrilateral cannot be a parallelogram nor can it be a rhombus since it has only one pair of equal angles.

The given quadrilateral also cannot be a trapezium because adjacent angles are not supplementary. Infact, there are no two angles pair which are supplementary.