Please help it is due at 4:30

If you were constructing a triangular frame, and you had wood in the length of 4 inches, 4 inches, and 7 inches, would it make a triangle? would you be able to create a frame from these pieces of wood?

Which graph or graphs appear to show a sinusoid? < me asap !

What is the solution to the system of equations? 10x+3y=8 -9x-y=-20 (11, 1) (1, 11) (–1, 11) (11, –1)'