A ladder leaning against a wall makes an angle of 60° with the ground. If the length of the ladder is 19 m, find the distance (in meters) from the foot of the ladder from the wall.
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 9.5 m
The ladder, the wall and the ground form a right-angled triangle with the ladder as the hypotenuse. The distance of the foot from the wall is the side next to the 60° angle, so it comes from the cosine of that angle.
The cosine is the side next to the angle over the hypotenuse: \(\cos60^\circ=\displaystyle\frac{\text{distance}}{19}\)
With \(\cos60^\circ=\frac{1}{2}\), the distance from the wall is \(19\times\frac{1}{2}=9.5\) m
