You can put this solution on YOUR website!
draw the ground, a wall and a line denoting the ladder. This situation is a right angled triangle, so you can use the basic trig relationships.
For the angle you are asked for, we know the height of the wall (opposite side) and the length of the ladder (hypotenuse)
sinA = 8/12 --> 2/3
so angle A = sin^(-1)(2/3)
which is something...use your calculator.