Question

the top surface of a table is in shape of a regular octagon as shown in the figure find the area of octangon​

Answer 1

Answer:

area of regular octagon =2(1+root2 )a²

=2(1+root2) 5²

= 120.71

Answer 2

Answer:

119

Step-by-step explanation:

• in regular octagon app sides are equal, there fore side=5cm
• octagon is divided into one rectangle and two congruent trapeziums
• area of octagon = area of two congruent trapeziums +area of rectangle

$area \: of \: trapezium = \frac{1}{2} (a + b) \times h$

1. area of trapezium = (1÷2)(5+13)(3) = 27 cm^2
2. two trapeziums so 2×27 = 54cm^2.

$area \: of \: rectangle = \: l \times b$

1. area of rectangle =13×5 =65cm^2.

area of octagon =54+65 =119cm^2