Bassima evaluated the expression below. what was bassimas error

What are the measures of ∠a, ∠b, ∠c and ∠d? explain how to find each of the angle measure.

Julie goes to the sports store and spends $40.50 before tax. she buys a pair of shorts for $21.75 and 3 pairs of socks that each cost the same amount. how much does each pair of socks cost? $$

The given diagram shows the parts of a right triangle with an altitude to the hypotenuse. using the two given  measures, find the other four.