How do you use the pythagorean theorem to solve for the missing side given a = 7, c = 21?

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Answer 1 · 2016-08-23T19:37:26

#b = 14sqrt2#

There are 2 possible answers, depending on whether #c# represents the hypotenuse or one of the shorter sides.

From #a^2 + b^2 = c^2#, one assume that #c# is the hypotenuse, but it should be stated.

From #a^2 + b^2 = c^2# we can also get #b^2 = c^2 - a^2 # if we are looking for one of the two shorter sides.

#b^2 = 21^2 - 7^2#

#b^2 =392#

#b = sqrt392 = sqrt(2xx4xx49)#

#b = 14sqrt2#