Perimeter is calculated as 2(w+l) or w+w+l+l. When you put those two numbers into the equation 2(10+18) or 10+10+18+18, you get the exact same answer of 56, and since 10 is eight less than 18, it would be the width.
Derive the equation of the parabola with a focus at (6, 2) and a directrix of y = 1. A f(x) = −1/2 (x − 6)2 + 3/2. B f(x) = 1/2 (x − 6)2 + 3/2. C f(x) = −1/2 (x + 3/2)2 + 6.
