A loft ladder is leaning against a house when it's base Starts to slide away . By the time the base is 8 it from the house , the base is moving away at the rate of 12 4 / sec . a. what is the rate of change of the height of the top of the ladder ? b. At what rate is the area of the triangle formed by the ladder wall , and ground changing then ? C. At what rate is the angle between the louder and the ground charging then