The length of one leg of a right triangle is 21 ft and the length of the hypotenuse is 29 what's the length of the other leg

You need to use the steps of a^2+b^2=c^2
A and B are the legs. C is the hypotenuse. 

If we follow that through, we find the answer is 20. 

In the first triangle 80+20+p=180 (since sum of all angles of a triangle is 180)so p= 80also in second triangle 55+45+q=180 (since sum of all angles of a triangle is 180)so q=80so we can conclude that p=80 degrees q=80 degrees so p=q=80 degreeshence option b is correct

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