Answer:
A) 9
Step-by-step explanation:
First you need to find the measure of angle c
Since it's a quadrilateral, the interior angles add up to 360 degrees
Now there's two right angles and one 99 degree angle
Add those and subtract from 360
360 - (90+90+99) = 81
C = 81 degrees
However x is the root of c so root 81 is 9
