Question

HELP!

Answer 1

Answer:

Step-by-step explanation:

Alright, lets get started.

Please refer the diagram I have attached.

There will be 8 triangles made.

The center angle will be = $\frac{360}{8}=45$

The triangle will be formed an isosceles triangle, so remaining angle will be :

$\frac{180-45}{2}=67.5$

$sin 67.5=\frac{opposite}{5}$

opposite= CD = $5sin67.5=4.6194$

Similarly,

adjacent = BD = $5cos67.5=1.9134$

The complete AB will be = $2*1.9134=3.8268$

Area of triangle ABC will be = $\frac{1}{2}*base*height = \frac{1}{2}*3.8268*4.6194=8.838$

So, the area of octagon will be 8 times area of this triangle.

Area of octagon will be = $8*8.838=70.70$

Hence are the area of octagon is  70.70 :   Option D  :   Answer

Hope it will help :)

Answer 2

the answer is d I know this one