Step-by-step explanation:
Area=(a+b)/2 x h
a=6x+3
b=4x-5
h=-5x+10
Area= -25x^2+55x-10
The formula for a triangular pyramid is 1/3AH. A is the area of the base. H is the height of the pyramid. So to find the area of a right triangle, you would use the formula (a x b)/2. So (10 x18)/2 is 90 inches^2. Now you can fill in the first formula. 1/3(90 x 14), which equals 420 inches^3. I hope you find this helpful (if correct.)
685,000,000 would be the right number. Hope this helps!
