The angle of elevation of a ladder leaning against a wall is 60° and the foot of the ladder is 4.6 m away from the wall. The length of the ladder is
Choose the correct choice from the following choices:	A) 2.3 m	B) 4.6 m	C) 7.8 m	D) 9.2 m	E) none

Rationale: solution let ab be the wall and bc be the ladder . then , < abc = 60 ° ac = 4.6 m . ; ac / bc = cos 60 ° = 1 / 2 ‹ = › bc = 2 × ac = ( 2 × 4.6 ) m = 9.2 m answer d
Answer: D