Answer:
The value of the angle x is 140°
Step-by-step explanation:
In the given figure
∵ The figure has 4 sides
∴ The figure is a quadrilateral
∵ The measure of the interior angle of the quadrilateral is 360°
∴ The sum of the angles inside the quadrilateral = 360°
∵ One of the vertices of the quadrilateral has an exterior angle of
measure 90°
∵ The sum of the interior angle and the exterior angle at a vertex = 180°
∴ The measure of the interior angle = 180° - 90°
∴ The measure of the interior angle = 90°
∵ The measures of the interior angles of the quadrilateral are 60°, 70°,
x, 90°
∴ 60° + 70° + x + 90° = 360°
→ Add the like terms in the left side
∴ 220° + x = 360°
→ Subtract 220 from both sides
∴ 220 - 220 + x = 360 - 220
∴ x = 140°
∴ The value of the angle x is 140°
