This requires the pythagorean theorem: a^2+b^2=c^2 where "a" and "b" are legs and c is the hypotenuse(longest side of the triangle which is opposite to the 90 degree angle.) If we fill the equation where c is the ladder length(11) and "a" is the distance from the house(), and "b" is the height, 9^2+b^2=11^2 or 81+b^2=121. This is equivalent to b^2=40. b=6.3 when rounded to the nearest tenth.
