Three interior angles of a quadrilateral measure 55°, 117°, and 120°. what is the measure of the fourth interior angle? 68° 78° 88° 98°

Option A. 68°

Step-by-step explanation:

As we know the sum of any polygon can be represented by 180(n-2).

Here interior angles of a quadrilateral have been taken.

Therefore sum of all interior angles will be = (4 - 2)× 180 = 2×180° = 360°

Three angles are 55°, 117°, 120° and we have to find fourth interior angle.

So 55 + 117 + 120 + x = 360 (x is the fourth angle)

292 + x = 360

x = 360 - 292 = 68°

Therefore Option A. 68° is the answer.

the answer is 99.