SOH CAH TOA

In any right-angled triangle:
Sine = opposite/hypotenuse
Cosine = Adjacent/hypotenuse
Tangent = Opposite/Adjacent

SOH CAH TOA:

Let ABC be a right-angled triangle. AB = 5cm, ∠ABC = 90º, ∠BAC = 40º. Find BC.
sin(40º) = BC/5
BC = 5sin(40º)
BC = 3.21cm (3sf)

by Josie wosie July 04, 2025