Question

9) Three angles of a quadrilateral are equal. The
fourth angle is 120°. Find the measure of the
equal angles.​

Answer 1

EXPLANATION:-

Let the three same angle be x,x,x

so x+x+x+120=360[ANGLE SUM PROPERTY]

3x+120=360

3x=360-120

3x=240

x=240/3

x=80

So the remaining 3 angles are 80,80,80.

Answer 2

Given :-

Three angles of a quadrilateral are equal. The  fourth angle is 120°

To Find :-

Measure of fourth angle

Solution :-

Let the similar angles be x,x and x

x + x + x + 120 = 360

3x + 120 = 360

3x = 360 - 120

3x = 240

x = 240/3

x = 80

Therefore

Measure of equal angles are 80°