Maths Dictionary · JSS 3, SS 1

Sine (sin)

Simple meaning

In a right-angled triangle, sin θ = opposite ÷ hypotenuse.

Example

sin 30° = 12.

See it

From the Sine, Cosine and Tangent lesson. Try moving things around.

θadjacent 7.99opposite 6.02hyp 10
sin 37°opphyp6.02 ÷ 100.6018
cos 37°adjhyp7.99 ÷ 100.7986
tan 37°oppadj6.02 ÷ 7.990.7536

Change the hypotenuse: the sides change, but the ratios for the same θ stay the same.

Angle θ37°
Hyp.10