You can focus on the two sub-triangles ABC and ACD
We know that they are both right triangles, because we're given that AC and BD are perpendicular.
The sides AB and AD are the hypothenuses of these triangles, so we know their length through the pythagorean theorem:
But since we're given 
, the expressions for AD and AB are actually the same expression. This proves that AD=AB, and thus that the triangle is isosceles.
That look hard what subject is it
Sonia saves a lot of water. To figure this out, you plug the number 8 into the equation, replacing it with the variable x. y = 3(8). Therefore, y=24. To find out how much water she saves, you have to also figure out how much water she was using for 8 minutes with the other shower head, the one that wastes the water. Since it dispenses 12 gallons per minute, you multiply that by 8 minutes and get 96. Subtract 24 from 96 and get 72. Which I think is your answer. Then again, I'm in high school so I most likely am wrong.
Answer:
r = 6 in
Step-by-step explanation:
= 
r²h/3 = 216
r² (18/3) = 6 r² = 216
r² = 216/6 = 36
r = 6
