Question

Please help if you can xx

Answer 1

Below in bold.

Explanation:

The angle in a regular octagon = 180 - (360/8) = 135.

Using trigonometry sin (135/2) = k/2 / EF

sin 67.5 = k / 2EF

2EF = k / sin 67.5

EF = k / 2 sin 67.5 = k/1.8478

Perimeter of octagon = 8 * k/1.8478

= 4.33k to the nearest hundredth.