Angle Sum Property of Quadrilateral – The sum of all angles of a quadrilateral is 360˚
Examples based on Angle Sum Property of Quadrilateral
Question 1
The measure of three angles of a quadrilateral are 100˚, 80˚, 120˚. Find the measure of the fourth angle?
Explanation
As we know that,
The sum of all angles of a quadrilateral = 360˚
100˚ + 80˚ + 120˚ + x = 360˚
300˚ + x = 360˚
x = 360˚ – 300˚
x = 60˚
Hence, the fourth angle of the quadrilateral is 60˚.
Question 2
The measure of three angles of a quadrilateral are 125˚, 65˚, 35˚. Find the measure of the fourth angle?
Explanation
As we know that,
The sum of all angles of a quadrilateral = 360˚
125˚ + 65˚ + 35˚ + x = 360˚
225˚ + x = 360˚
x = 360˚ – 225˚
x = 135˚
Hence, the fourth angle of the quadrilateral is 135˚.
