Question

A quadrilateral has three angles that measure 80Á, 110Á, and 75Á. Which is the measure of the fourth angle?Select one of the options below as your answer: A. 50Á B. 90Á C. 95Á D. 125Á

Answer 1

Sum of all the angles in Quadrilateral is equal to 360

so, 360 = 80+110+75+x

x = 360-265

x = 95

OPTION C IS YOUR ANSWER.

Answer 2

C.
`95^(\circ)`

Explanation:

Let x represent 4th angle of the given quadrilateral.

We have been that a quadrilateral has three angles that measure
`80^(\circ)`,
`110^(\circ)` and
`75^(\circ)`. We are asked to find the measure of the fourth angle.

We know that all the interior angles of a quadrilateral are equal to 360 degrees, so we can set an equation as:

`x+80^(\circ)+110^(\circ)+75^(\circ)=360^(\circ)`

`x+265^(\circ)=360^(\circ)`

`x+265^(\circ)-265^(\circ)=360^(\circ)-265^(\circ)`

`x=95^(\circ)`

Therefore, the measure of 4th angle is 95 degrees and option C is the correct choice.