How do you find the area of a regular hexagon with a radius of 5? Please show working.

1 Answer
May 9, 2018

A = (75 sqrt(3))/2 ~~65 " units"^2

Explanation:

Given: a regular hexagon with radius = 5

A = 1/2 a P, where a = apothem , P = perimeter

The apothem is the perpendicular distance from the center to a side.

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n = number of sides = 6

s = side length = 2x

P = ns = 6s = 6(2x) = 12x

A = 1/2a(12x) = 6ax

2 theta = (360^@)/n = 360/6 = 60^@

theta = (60^@)/2 = 30^@

Use trigonometry to find a and x given r and theta:

(sin 30^@)/1 = x/r = x/5; " " x = 5 sin 30^@ = 5 (1/2) = 5/2

(cos 30^@)/1 = a/r = a/5; " " a = 5 cos 30^@ = (5 sqrt(3))/2

A = 6ax = 6 ((5 sqrt(3))/2) (5/2) = (75 sqrt(3))/2 ~~64.95 " units"^2