Question

The sum of 3 angles of a heptagon is 340°. The remaining angles are equal in size to each other. Calculate each size of the equal angles.​

Answer 1

equal angles are 140°

Explanation:

A heptagon has 7 sides

the sum of the interior angles of a polygon is

sum = 180° (n - 2) ← n is the number of sides

then for a heptagon

sum = 180° × 5 = 900°

let each of the equal angles be x , so

4x + 340° = 900° ( subtract 340° from both sides )

4x = 560° ( divide both sides by 4 )

x = 140°

each of the equal angles are 140° in size.