Question 78178
Part A looks good.(nearest tenth implies 1 decimal place)

The 20 foot ladder has moved 22 ft down the building!!!!

After the bottom of the ladder has moved out an extra 3 feet the angle at the top is no longer 22 degrees.

You have a right angle triangle with a hypotenuse of 20 feet and a base of 10.5 feet. Use Pythagoras to solve this one.
{{{c^2=a^2+b^2}}}
{{{b^2=c^2-a^2}}}
{{{b^2=20^2-10.5^2}}}
{{{b^2=400-110.25}}}
{{{b^2=289.75}}}
{{{b=sqrt(289.75)}}}
b=17 feet

In the same way find the original height of the ladder on the building.
{{{c^2=a^2+b^2}}}
{{{b^2=c^2-a^2}}}
{{{b^2=20^2-7.5^2}}}
{{{b^2=400-56.25}}}
{{{b^2=343.75}}}
{{{b=sqrt(343.75)}}}
b=18.5 feet

So the ladder has slipped down an extra 1.5 feet.