Ahouse is 20 feet tall and it cast a shadow 50 feet long. there is a nearby building that, at the same time, casts a shadow 420 feet long. how tall is the building

Well that would make the building 390 feet tall.

(c, 0) i might be wrong so don't put full faith on my answer

fist on the left goes with the third on the right. second on the left goes with the fourth on the right. third on the left goes with the second on the right. the fourth on the left goes with first on the right