Question

what is the sum of the interior angles of an octagon?
1,260°
1,080°
900°
1,440°

Explanation:

Step1: Recall the formula

The formula for the sum of interior - angles of a polygon is $(n - 2)\times180^{\circ}$, where $n$ is the number of sides of the polygon.

Step2: Identify the value of n

An octagon has $n = 8$ sides.

Step3: Calculate the sum

Substitute $n = 8$ into the formula: $(8 - 2)\times180^{\circ}=6\times180^{\circ}=1080^{\circ}$.

Answer:

B. $1,080^{\circ}$