I need help ASAP please show your work

In triangle △abc, ∠abc=90°, bh is an altitude. find the missing lengths. ah=4 and hc=1, find bh.

Match the scale and the actual area to the area of the corresponding scale drawing. scale: 1 inch to 4 feet actual area: 128 square feet scale: 1 inch to 7 feet actual area: 147 square feet scale: 1 inch to 8 feet actual area: 256 square feet scale: 1 inch to 5 feet actual area: 225 square feet area of scale drawing scale and actual area scale drawing area: 3 square inches arrowright scale drawing area: 8 square inches arrowright scale drawing area: 4 square inches arrowright scale drawing area: 9 square inches arrowright

Which property was used to simplify the expression? 3c+9 +4c=3c+4c+9