volume of the red prism = h1 * B1
volume of the blue prism = h2 * B2
area of the base of the red prism = 1/3 * the area of the base of the blue prism.
you get B2/3.
volume of the red prism = h1 * B2/3.
volume of the blue prism is still h2 * B2.
since the volumes are equal, you get:
h1 * B2/3 = h2 * B2
divide both sides of this equation by B2 and you get:
h1/3 = h2
multiply both sides of this equation by 3 and you get:
h1 = 3 * h2.
if the area of the base of the red prism is 1/3 * the area of the base of the blue prism, then the height of the red prism is 3 times the height of the blue prism.