SOLUTION: I'm studying for the GRE and math isn't my best subject. I have a rectangular solid with length 7, width 10, and height 2. I need to find the diagonal of this solid. I did the Pyth

Algebra ->  Bodies-in-space -> SOLUTION: I'm studying for the GRE and math isn't my best subject. I have a rectangular solid with length 7, width 10, and height 2. I need to find the diagonal of this solid. I did the Pyth      Log On


   



Question 912947: I'm studying for the GRE and math isn't my best subject. I have a rectangular solid with length 7, width 10, and height 2. I need to find the diagonal of this solid. I did the Pythagorean triangle equation of 10 squared + 7 squared= c squared. Long story short I got v149 (square root), which is equal to 12.2. However, the correct answer was 3 times the square root of 17, which is 12.36. How am I supposed to get to that form of the answer? My calculator will only show an answer with decimals, not a simplified equation like 3√17 to We're not allowed TI-84 calculators, just basic ones. I need to be able to figure out that type of answer in a short period of time (the section of the test is only 25min) Help!
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
D =
Note: Diagonal is from corner to corner
(base diagonal)^2 = l^2 + w^2
D^2 = (l^2 + w^2) + h^2
thus..
D = sqrt%28L%5E2+%2B+w%5E2+%2B+h%5E2%29