Question 759375
Pythagoras.
Ladder represents the hypotenuse
of a right angled triangle.
The base side = 5 (20/4)
To find the height.
 hypotenuse^2 = base^2 + height^2
 height^2 = hypotenuse^2 - base^2
          = 20^2 - 5^2
          = 375
   height = square root 375
          = 19.4 ft
Therefore 19.4ft + 3ft = 22.4ft house can be painted.
Hope this helps.
:-)