Solution: (1) If the base length is 20m and the waist height is x meters as the root number (x square-100), the area = root number (x square-100) *10 =160, and x = Let the height of the base X be the root sign (square of 400-65438 +0/4*x) (pay attention to the order, calculate the square first, multiply and divide, and then subtract) and the area = 1/2 *x* root sign (square of 400-65438+0/4 * x) = 6544.