Question 944811
use Pythagorean theorem: {{{c^2=a^2+b^2}}}



if in a right triangle, the length of the hypotenuse is {{{c=20in}}} and the length of one leg is {{{a=15in}}}, then

 the length of the other leg {{{b}}} is:

{{{(20in)^2=(15in)^2+b^2}}}

{{{400in^2-225in^2=b^2}}}

{{{175in^2=b^2}}}

{{{b=sqrt(175in^2)}}}

{{{b=sqrt(25*7)in}}}

{{{b=5*sqrt(7)in}}}


so, your answer is:A. 5√ 7