The Area of a Triangle (Leaving Cert Mathematics): Flashcards

Capital letters (A, B, C)

Lowercase letters (a, b, c)

Side a

$\frac{1}{2}ac \sin B$

$\frac{1}{2}ab \sin C$

Between the two sides

$\sin C = \frac{2 \times \text{Area}}{ab}$

Degree mode

$\sin^{-1}$ (inverse sine)

Units

Sine of angle between them

Angle not between the two sides used