Answer:
11.6feet
Step-by-step explanation:
1) The whole question set up will give a right angled triangle as shown;
Wea re to calculate the height of the wall. Using the pythagoras theorem;
Length of ladder = Hypotenuse = 12feet
Adjacent = 3feet
Height of the wall = opposite
Hyp^2 = Opp^2 + Adj^2
12^2 = Opp^2 + 3^2
144 = Opp^2 + 9
Opp^2 = 144-9
Opp^2 = 135
Opp = \sqrt[135]
Opp = 11.6feet
Hence the height above the ground that the ladder touches the wall is 11.6feet