Question

find cosec 30° and cos 60° graphically.

Answer 1

Let ΔABC be an equilateral triangle in which each side is of length 2a. Draw AP perpendicular to BC.

Now, BP = PC = a  [ perpendicular drawn from the vertex to a side of an equilateral triangle always bisect it]

∠B = 60°         [all angles in equilateral triangle is equal to 60°]

Now, cosθ= base/ hypotenuse

 cos 60° = a / 2a  

it means cos 60 ° = 1/2

Now apply Pythagoras theorem  in ΔAPB ,

 

cosec θ= hypotenuse / perpendicular

so , cosec  60°= 2/√3