Atriangle shaped wall is 7 feet long and 9 feet wide. how long is the diagonal of triangle?

Alake near the arctic circle is covered by a 222-meter-thick sheet of ice during the cold winter months. when spring arrives, the warm air gradually melts the ice, causing its thickness to decrease at a constant rate. after 333 weeks, the sheet is only 1.251.251, point, 25 meters thick. let s(t)s(t)s, left parenthesis, t, right parenthesis denote the ice sheet's thickness sss (measured in meters) as a function of time ttt (measured in weeks).

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

What is sin 7x/4 ? i need on this urgent trig