If the number of members (m) in a pin-jointed frame is ________, the frame is known as a deficient frame (where j is the number of joints).

If a truss span increases but the depth and the loads remain constant, the internal forces in the members of the truss will ________.

A pin-jointed frame having 'm' number of members and 'j' number of joints is said to be a perfect frame if it satisfies which of the following equations?