If CDEF is a rhombus, find angle FED

Which statement justifies why angle ebc measures 90?

Look at this pattern ; 1,4,9, number 10000 belongs in this pattern . what’s the place of this number?

Two cars which are 40 miles apart start moving simultaneously in the same direction with constant speeds. if the speed of the car which is behind is 56 mph and the speed of the other car is 48 mph, how many hours will it take for the car which is behind to catch up the car ahead of it?