A ladder lying against a wall has a 60-degree angle of elevation, and the ladder's foot is 4.6 metres distant from the wall. The ladder's length is as follows:
A. 2.3 m
B. 4.6 m
C. 7.8 m
D. 9.2 m
Answer:D
A ladder lying against a wall has a 60-degree angle of elevation, and the ladder's foot is 4.6 metres distant from the wall. The ladder's length is as follows:
A. 2.3 m B. 4.6 m C. 7.8 m D. 9.2 m
Explanation: Assume that AB represents the wall and BC represents the ladder.Then ACB = 60° and AC = 4.6 m are calculated. AC/BC = cos 60° = 1/2 , BC = 2 x AC = (2 x 4.6) m = 9.2 m