Express the area and perimeter of an equilateral triangle as a function of the triangle's side length x?

perimeter = 3x Area = x^2 * sqrt(3)/4 Explanation of area: You can divide an equilateral triangle into 2 right triangles, each with a common side we will call y. Area = area of first right triangle + area of second right triangle = (x/2)*y/2 + (x/2)*y/2 = xy/2 Now: y^2 + (x/2)^2 = x^2 so y^2 = x^2 - x^2/4 so y= sqrt(3)x/2 Area = [sqrt(3)x/2] x [x/2] Area = x2 sqrt (3)/ 4