The reciprocal trigonometric ratios: cosecant
It is said that there are six ratios possible for the lengths of the sides of a
right triangle. You have learned about the sine (sin), cosine (cos), and tangent (tan)
ratios. The three other trigonometric ratios are their reciprocals.
Cosecant (csc): is the reciprocal of sine, i.e. the ratio of the length of the hypotenuse to the length of the opposite side.
csc θ 
= 
_1_
sinθ 
= 
hyp
opp 



Find the value of cscB 


First find the length of the hypotenuse. Using the Pythagorean Theorem, or recognizing the Pythagorean Triple 51213, the length of the hypotenuse is 13.