How many sides does an n-gon have if the sum of its angles is 1260?

The form for finding the sum of the angles of any shape looks like this
(n-2) × 180
First you need to find out how many angles this figure contains.
To do this, let’s designate x-th – the number of angles.
And find x using the equation.
(x-2) × 180 = 1260
180x-360 = 1260
180x = 1260-360 = 900
x = 900 ÷ 180
x = 5
This figure has five corners.
And since around any corner in the figure consists of two sides, the sides are twice as many in this figure as the corners.
That is, 5 × 2 = 10
Answer: 10 sides