Trigonometry 1 (Edexcel GCSE Maths): Flashcards

Tools to find angles in right triangles from two sides

Longest side opposite the right angle

Side touching the angle (not hypotenuse)

Side not touching the angle being calculated

Hypotenuse

$\sin x° = \frac{\text{opposite}}{\text{hypotenuse}}$

$\cos x° = \frac{\text{adjacent}}{\text{hypotenuse}}$

$\tan x° = \frac{\text{opposite}}{\text{adjacent}}$

Mnemonic for remembering trig ratios

Sine = Opposite ÷ Hypotenuse

Cosine = Adjacent ÷ Hypotenuse

Tangent = Opposite ÷ Adjacent

Right-angled triangles only

$\sin^{-1}$, $\cos^{-1}$, $\tan^{-1}$

Degree mode (D symbol)