Use a proportion if two cassettes cost $14.50 how much will 15 cost

Which formula gives the area of a triangle? a=1/2(b+h)

How do i work this problem out using the equation a=pe^rt

50 ! pls ! 12.  building codes regulate the steepness of stairs. homes must have steps that are at least 13 inches wide for each 8 inches that they rise.

a. discuss how to find the slope of the stairs.
b. describe how changing the width or height affects the steepness of the stairs.