There are 80 tens. write how many hundreds. write the number

Aphrase is shown read the phrase and give me the answer

Present age of man is 45 years, 5 years back his age was 4 times age of his son what is present age of his son?

Plzz ! 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? yes or no? = explain your mathematical thinking/show your work: