Question

Three angles of a quadrilateral are equal and fourth one is 120°. Find the measure of these 3 equal angles of the quadrilateral.

Answer 1

Answer:

80 degree

Step-by-step explanation:

Let x be one the three equal angles.

Sum of all the angles of a quadrilateral = 360o

⇒ x + x + x + 120o = 360o

⇒ 3x = 360o -120o

⇒ 3x = 240o

⇒ x = 80o

Thus, the measure of each of the equal angle is 80o

Answer 2

Step-by-step explanation:

let sum of all the angles which are equal be - X

In a quadrilateral,

sum of all four angles is 360 degree

(name four angles as 1, ,2, 3 and 4)

1+2+3+4= 360

x + x + x + 120 = 360

3x = 360 - 120

3x = 240

x = 240÷3

x = 80

Therefore the angles which are equal to one another is of 80 degrees each..

.

.

.

Thank you