question_answer 14)

                Top surface of a raised plat form is in the shape of a regular octagon as shown in the figure. Find the area of the octagonal surface.

Answer:

                Area of the octagonal surface  = Area of rectangular portion        + 2(Area of trapezoidal portion) \[=11\times 5+2\times \left[ \frac{(5+11)\times 4}{2} \right]\,{{m}^{2}}\] \[=55+64\,{{m}^{2}}\] \[=119\,{{m}^{2}}\].