Minus always used a term

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

If you have a set of parallel lines a and b cut by transversal x, if angle 1 = 167 degrees, what is angle 4 and why. also what is the measure of angle 5 and why? you need to use the names of the angle relationship and explain.

Hello, i need compare km^2 and km. what's difference in this?