Question

If three angles of a quadrilateral are ${50}^{\circ },{70}^{\circ }$ and ${160}^{\circ }$ then the fourth angle of the quadrilateral is:

• A. 120^o
• B. 180^o
• C. 240^o
• D. 60^o

Answer 1

The correct option is B

180^o

According to the angle sum property of a quadrilateral, the sum of all the angles of a quadrilateral is $={360}^{\circ }$

$\therefore$The fourth angle $={360}^{\circ }-({50}^{\circ }+{70}^{\circ }+{160}^{\circ })$ $={360}^{\circ }-{280}^{\circ }$ $={80}^{\circ }$