So to solve you need to set up equations, Using h as the height. So the base is 9 inches more (+9) than 3 times the height (3h) so 3h+9 equals the base. You have the area so you need to plug in the equation for the base and h for height and divide it all by 2. h(3h+9)/2=105. after you solve that and get h by itself you should get h= 7 and the b= 30
