Find the number of sides of a polygon if the number of its diagonals is 90.

Find the number of diagonals in a polygon having 10 sides.

If a polygon has 44 diagonals,find the number of its sides.

Which polygon has the same number of diagonals as the number of its sides?

What can you say about the angle sum of a convex polygon with number of sides 7 ?

Prove that the sum of the squares of the sides of a rhombus is equal to the sum of the squarea of its diagonals.

Examine the table. (Each figure is divided into triangles and the sum of the angles deduced from that.) What can you say about the angle sum of a convex polygon with number of sides? 10

A polygon has 5 diagonals.Find the number of sides.

Find the number of diagonals that can be drawn the joining angular points of a Hexagon.

Find the number of diagonals that can be drawn the joining angular points of a Heptagon.

Find the number of diagonals that can be drawn the joining angular points of a Decagon.