question_answer

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

Answer:

Each side of octagon surface = 5 m

Area of octagon = 2(Area of trapezium) + Area of rectangle

\[=2\times \frac{1}{2}\times h\times \] (sum of parallel side) \[+\text{ l }\times \text{ }b\]

\[=4\times \left( 5+11 \right)+11\times 5~\]

= 64 + 55

= 119 \[{{m}^{2}}\]

Area of octagon surface = 119 \[c{{m}^{2}}.\]