Answer:
34.5 feets
Explanation:
Length of ladder = 37 feet
Angle between ladder and top of building = 21°
Since ladder makes a right angle with the foot of the wall;
Angle the ladder makes with the ground :
(90° + 21° + θ) = 180°
111° + θ = 180°
θ = 180° - 111°
θ = 69°
To obtain the height, x of the building reached by the ladder ;
Using Pythagoras :
Sinθ = opposite / hypotenus
Sin 69° = x / 37
x = 37 * sin 69°
x = 37 * 0.9335804
x = 34.542475
x = 34.54 feets
Hence, the height up the building reached by the ladder is 34.5 feets