3/4-2/3=what does it equal

In the 30-60-90 triangle below side s has a length of and side r has a length

Determine the number of outcomes in the event. decide whether the event is a simple event or not. upper a computer is used to select randomly a number between 1 and 9 comma inclusive. event upper b is selecting a number greater than 4. event upper b has nothing outcome(s). is the event a simple event? (yes or no) because event upper b has (fewer than, exactly, more than) one outcome.

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