A ladder 14 m long just reaches the top of a vertical wall. If the ladder makes an angle of 60° with the wall, then the height of the wall is:

Length of ladder (hypotenuse), L = 14 m
Angle with wall, θ = 60°
Height of wall (adjacent side) = H

Formula used:
cos θ = $$\frac {H}{L}$$​​

Solution:
cos 60° = $$\frac {H}{14}$$​ 
=> $$\frac {1}{2}$$​ = $$\frac {H}{14}$$​​
=> H = 14 × 1/2
=> H = 7 m