Disappearing triangle? An equilateral triangle initially has sides of length 20 ft when each vertex moves toward the midpoint of the opposite side at a rate of 1.5 ft/min. Assuming the triangle remains equilateral, what is the rate of change of the area of the triangle at the instant the triangle disappears?

Solution: Step1 To find what is the rate of change of the area of the triangle at the instant the triangle disappears Step2 Given that An equilateral triangle initially has sides of length 20 ft when each vertex moves toward the midpoint of the opposite side at a rate of 1.5 ft/min. Assuming the triangle remains equilateral. Step3 Step4 We are Assuming the triangle remains equilateral.when...