গাণিতিক যুক্তি MCQ
The angle of elevation of a ladder leaning against a wall is 60º and the foot of the ladder is 3.5 m away from the wall. The length of the ladder is-
সঠিক উত্তর
7 m
Let AB be the wall and BC be the ladder. Then, ∠ACB = 60° ⇒ AC = 3.5 m⇒ AC/BC= cos60∘⇒ AC/BC= 1/2⇒ BC = 2 × AC ⇒ BC = 2 × 3.5 ⇒ BC = 7 m