Hey guys stuck on three questions, can you help out a bit? Thanks!

The square pyramid has a volume of 441 cubic inches. what is the value of x? 1/7x is the height x is the base

1) in triangle the, what is the measure of angle t (in degrees)? 2) in triangle bat, the measure of angle b is 66∘, and the measure of angle t is 77∘.what is the measure of the exterior angle at a (in degrees)?

Jack did 3/5 of all problems on his weekend homework before sunday. on sunday he solved 1/3 of what was left and the last 4 problems. how many problems were assigned for the weekend?