?

Me find the missing dimension of a triangle height: 7 in., area: 21^2

Awater holding tank measures 105 m long, 50 m wide, and 8 m deep. traces of mercury have been found in the tank, with a concen- tration of 60 mg/l. what is the total mass of mercury in the tank? answer in units of kg.

If cos(2x) = tan^2(y), show that cos(2y) = tan^2(x).