A 13 ft ladder is leaning against a house when its base begins to slide away. By the time the base is 3 ft from the house, the base is moving at the rate of 2 ft/sec. Answer the following:

At what rate is the area of the triangle formed by the ladder, wall, and ground changing then?

I get A' = (1/2)(2)(sqrt(160)) + (1/2)(3)(12/(2sqrt(160)))

But this isn't right and I'm having trouble finding my error..

also, dh/dt = (12/(2sqrt(160))

Question

A 13 ft ladder is leaning against a house when its base begins to slide away. By the time the base is 3 ft from the house, the base is moving at the rate of 2 ft/sec. Answer the following: 

At what rate is the area of the triangle formed by the ladder, wall, and ground changing then?

I get A' = (1/2)(2)(sqrt(160)) + (1/2)(3)(12/(2sqrt(160))) 

But this isn't right and I'm having trouble finding my error..

also, dh/dt = (12/(2sqrt(160))

anonymous · Answer

Sorry forgot one closing ) on a couple of those but that isn't my problem..