So, basically we are making a unit circle on a cartesian plane with its center as the origin, lets take "b" to be the y coordinate of any point and "a" to be the x coordinate.

If i take a certain point (a,b) and make a right triangle from it, where the hypotenuse intersects the origin then since its a unit circle so hypotenuse = radius of circle =1

sinθ = b/1 = b

cosθ = a/1 = a

This is kinda confusing me, what if the denominator is not 1 ? Lets say the hypotenuse = 5cm and hence a =3cm and b = 4cm, sinθ = 4/5 and cosθ = 3/5.

sinθ = 4/5 not equal to b which has a value of 4 ?

cosθ = 3/5 not equal to a which has a value of 3 ?

I am a bit confused about how this works here