Answer:
The measure of the fourth angle is 81°
Step-by-step explanation:
we know that
The sum of the internal angles of a quadrilateral must be equal to 360 degrees
Let
x----> the measure of the fourth angle
we have
90°+90°+99°+x=360°
Solve for x
279°+x=360°
x=360°-279°=81°
