three interior angles of a quadrilateral measure 55°, 117°, and 120°. what is the measure of the fourth…
three interior angles of a quadrilateral measure 55°, 117°, and 120°. what is the measure of the fourth interior angle?\n68°\n78°\n88°\n98°
Answer
Explanation:
Step1: Recall angle - sum property
The sum of the interior angles of a quadrilateral is $360^{\circ}$.
Step2: Set up an equation
Let the fourth angle be $x$. Then $55^{\circ}+ 117^{\circ}+120^{\circ}+x = 360^{\circ}$.
Step3: Simplify the left - hand side
$55 + 117+120=292$, so the equation becomes $292^{\circ}+x = 360^{\circ}$.
Step4: Solve for $x$
$x=360^{\circ}- 292^{\circ}=68^{\circ}$.
Answer:
A. $68^{\circ}$