Question

The three angles of a quadrilateral are 100°, 60°, 70°. Find the fourth angle.

Answer 1

The three angles of the quadrilateral are 100°, 60°, 70°.

Let the fourth angle be x°,

Since, the sum of the angles of a quadrilateral is 360°.

∴ 100° + 60° + 70° + x° = 360°

230° + x° = 360°

x = 360° – 230° = 130°

Hence, the fourth angle is 130°.