A right triangle has legs that are 15 centimeter long and 7 centimeters long. What is the length of the hypotenuse? i know this is pythagoream theorem. And the 15 is under a radical sign.

Question

accessdenied · Answer

So, $ a^2 + b^2 = c^2 $, where $ a = \sqrt{15} $ and $ b = 7 $?

anonymous · Answer

oh right.
uhm. It's the legs.

anonymous · Answer

How would I solve the radical 15?

accessdenied · Answer

yeah, $a$ and $b$ would be the lengths of the legs and $c$ would be the hypotenuse.
Then we just solve for c by evaluating the left side and then taking its square root.

accessdenied · Answer

$ (\sqrt{15})^2 = 15 $

anonymous · Answer

Ohhh. I see So the answer would be about seventeen? The choices are 5, 8, 17, and 22

accessdenied · Answer

$ (\sqrt{15})^2 + 7^2 = c^2\
15 + 49 = c^2\
64 = c^2 $

anonymous · Answer

ohhh! so you don 't need to put 15 to the power of 2 i see. Thanks so much. :3

accessdenied · Answer

No problem.  :)
We just substitute the values we have into the Pythagorean theorem, and square roots will tend to disappear in the lengths because the lengths of the legs are always squared in that formula.

anonymous · Answer

Thank you. I'm such a blonde...even though I have black hair :P

accessdenied · Answer

Haha, I had a blonde moment (brown hair of course) today doing a sequence problem on a test.  My mind went completely blank on how to do it until after the test, when my friend told me how he did it.  :P