Mathematics
Grade9
Easy
Question
Find the area of the regular polygon.
- 35
- 32
- 21
- 24
Hint:
Polygon is a two- dimensional closed figure which is made up of three or more line segments. Each polygon has its own properties based on the number of sides. Area of a regular polygon can be determined using the formula 
. Here, we have to find the area of the given polygon.
The correct answer is: 21
In the question there is a polygon as shown in the figure above.
Here, we have to find the area of the given polygon.
From the figure we can say that, apothem= 2.5
Firstly, we have to find the length of each side of the polygon.
For that, let us consider length of the polygon be x.
So, tan 64.29 = 
x = 1.2
Then, length of each side(a) = 2×1.2 = 2.4
Perimeter(P) = 2.4 × 7 = 16.8
A = 
×a ×P
= ×2.5 × 16.8
= 21
So, the area of the given polygon is 21.
Therefore, the correct option is c, i.e., 21.
A perpendicular line segment joining the centre and one of the sides of the regular polygon is called apothem of the polygon.
