In sunlight, a vertical stick has a height of 3ft and casts a shadow 2ft long. at the same time, that a nearby tree casts a shadow 20ft long. how tall is the tree.

30 ft. tall. You must find the ratios and compare. 2/20=3/x The best way I know to do this is to cross multiply. 2 times x and 20 times 3. So, 2x = 60. Divide by 2 and you get x = 30. The height of the tree would be 30 ft. You could also find the proportion. 20/2 = 10, so the height, x, over 3 would be equal to 10. 3 times 10 is equal to 30.