To find the number of sides of a regular polygon when you know the sum of its interior angles, you can use the formula for the sum of interior angles of a polygon, which is:
Sum of interior angles = (n - 2) * 180°
where n is the number of sides.
We are given that the sum of the interior angles is 1440°. To find the number of sides, n, we can plug the value of the sum of the interior angles into the formula and solve for n:
1440° = (n - 2) * 180°
Now, we divide both sides of the equation by 180° to solve for (n - 2):
1440° / 180° = n - 2
This simplifies to:
8 = n - 2
Finally, we add 2 to both sides of the equation to solve for n:
n = 8 + 2
n = 10
Therefore, the regular polygon has 10 sides. The corresponding answer is (B) 10.
