A regular decagon has an apothem of 7 meters and a side length of 13 meters. What is its area?
Options
A
455 m²
B
450 m²
C
440 m²
D
435 m²
Answer & Analysis
Answer
A
Analysis
Question Analysis
The main focus is to calculate the area of a regular decagon. It requires using the formula for the area of regular polygons which involves the apothem and the perimeter of the polygon. This tests the understanding of geometric concepts related to regular polygon areas.
Key Concept Explanation
The formula for the area of a regular polygon is , where is the apothem (the perpendicular distance from the center of the polygon to the mid - point of a side) and is the perimeter of the polygon. For an sided regular polygon with side length , the perimeter .
Step - by - Step Solution
1. Calculate the perimeter :
A decagon has sides. Given the side length meters.
Using the formula , we substitute and . So, meters.
2. Calculate the area :
Given the apothem meters.
Using the area formula , we substitute
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