A ladder 9m long leans against a vertical wall, making an angle of 64° with the horizontal ground. calculate correct to one decimal place, how far the foot of the ladder is from the wall.
-
A.
4.0m -
B.
5.8m -
C.
7.1m -
D.
8.1m -
E.
18.5m
Correct Answer: Option A
Explanation
cos 64° = x/9x = 9 cos 64°
=3.94 ≅ 4.0m