Question

The sum of the four angles of a quadrilateral is $360°$

The angle of a quadrilateral are respectively $100°,98°,92°.$ The measure of fourth angle is:

• A. $70°$
• B. $290°$
• C. $98°$
• D. $92°$

Answer 1

The correct option is A

$70°$

Choose the correct option.

The given angles are $100°,98°,92°.$

let the fourth angle be $x°$

We know that the angle sum property of the quadrilateral.

$\begin{array}{rcl}100°+98°+92°+x°& =& 360°\\ x°& =& 360°-290°\\ & =& 70°\end{array}$

Hence, the fourth angle be $70°$

Hence, the correct option is A.