Question

6. Here is an octagon.

Answer 1

Answer:

a). Yes. Area will be less than 100 square in.

b). Area of octagon = 82 in²

Step-by-step explanation:

From the picture attached,

a). Octagon is inscribed in a square having one side = 10 inches.

Since, octagon is obtained by cutting off the four equal corners of the square,

Area of octagon will be less than the area of the square.

Area of square = (side)²

                         = 10²

                         = 100 in²

Therefore, area of octagon will be less than 100 in²

b). Since, corner cut off from the square are equal in shape and area,

   Area of one corner (right angle triangle) = $\frac{1}{2}(\text{Base})(\text{Height})$

                                                                      = $\frac{1}{2}(3)(3)$

                                                                      = 4.5 in²

   Area of 4 corners = 4.5 × 4 = 18 in²

   Area of octagon = Area of square - Area of 4 corners removed

                               = 100 - 18

                               = 82 in²