Question

an angle of quadrilateral is 120 the other three angle are equal find the measure of each of the equal angle

Answer 1

let equal angles be x

∴sum of angles of a quadrilateral =360°

=>x+x+x+120 =360°

=>3x+120°=360°

=>3x =360°-120°

=>3x=240°

=>x=240°/3 =80°

each of equal angle =80°

Answer 2

Step 1 - let one angle be x
Step 2 - other two be also 2x
Step 3 - fourth angle is 120
ATQ//
X+2x+120=360
3x+120=360
3x=360-120
3x=240
X=240/3
X=80