The given line passes through the points (−4, −3) and (4, 1). what is the equation, in point-slope form, of the line that is perpendicular to the given line and passes through the point (−4, 3)? y − 3 = (x + 4)

You are standing next to a really big circular lake. you want to measure the diameter of the lake, but you don't want to have to swim across with a measuring tape! you decide to walk around the perimeter of the lake and measure its circumference, and find that it's 400\pi\text{ m}400? m. what is the diameter dd of the lake?