Two equal sides, I, of an isosceles triangle are increasing at a rate of 0.5 cm/sec while the third side, b, is held at 20 cm. 1 = leg b = base h h = height b 2 (Note: Area of a triangle is A = - bh, where b is its base and h is the height) At what rate is the area of the triangle changing when the sides are all 20 cm? O Area is increasing O Area is decreasing At a rate of cm/sec