Question 1032266
.
A ladder is leaning against a building so that the distance from the ground to the top of the ladder is 3 feet less than the length of the ladder. 
Find the length of the ladder if the distance from the bottom of the ladder to the building is \sqrt(39) feet. 


<pre>
Vertical leg,     r-3

Horizontal leg,   {{{sqrt(39)}}}

Hypotenuse,        r
</pre>

{{{(r-3)^2 + 39}}} = {{{r^2}}},


{{{r^2 - 6r + 9 + 39}}} = {{{r^2}}},


{{{6r}}} = {{{39+9}}},


{{{6r}}} = {{{48}}},


r = {{{48/6}}} = 8 feet.