Answer: (D.)
The polygon has 9 sides
Step-by-step explanation:
We need to equate the given expression to the given value and solve for n.
The sum of the interior angles, s, in an n-sided polygon is given by the expression:
We want to use this formula, to calculate how many sides has a polygon if the sum of the interior angles is 1,260°.
We solve the following equation for n.
Divide through by 180 to get:
Add 2 to both sides to get: