Octagons have 8 sides. If each side is 5 feet then the perimeter is 40 feet. You add up the sides.
Step-by-step explanation:
Sin^2 (x) * Cos^2 (x) = {[1 - cos (2x)]/2}*{[1 + cos (2x)]/2}
Sin^2 (x) * Cos^2 (x) =[ 1 - cos^2 (2x)]/4
Sin^2 (x) * Cos^2 (x) = (1/4) - (1/4) * cos^2 (2x)
Sin^2 (x) * Cos^2 (x) = (1/4) - (1/4) * {[1 + cos (2*2x)]/2}
Sin^2 (x) * Cos^2 (x) = (1/4) - (1/8) * [1 + cos (4x)]
Sin^2 (x) * Cos^2 (x) = (1/4) - (1/8) - (1/8)* [cos (4x)]
Sin^2 (x) * Cos^2 (x) = (1/8) - (1/8)* [cos (4x)]
Subtract the 2x and divide by -4. y=1/2x-2 or y=x/2-2
Let x be the length and y be the width2x + 2y = 40x + y = 20change that into y = mx + b formy= 20 – x
Area =xy = x (20-x) = 20x - x^2Area=-x^2+20xcomplete the square:Area=-(x^2 – 20x + 100) +100=-(x - 10)^2 + 100This is an calculation of a parabola that opens downward with vertex at (10,100), which means maximum area of 100 happens when x, the length=10)Dimensions of the rectangle with maximum area? 10 yds. by 10 yds., a square.
