Triangle formulae

Is it a right-angled triangle?

Does the question include angles?

Trigonometry

sinθ = opp/hyp

cosθ = adj/hyp

tanθ = opp/adj

Pythagoras

a^2 + b^2 = c^2

c^2 - b^2 = a^2

c^2 - a^2 = b^2

Cosine rule

a^2 = b^2 + c^2 - 2bc CosA

A = Cos^-1 ((b^2 + c^2 - a^2)/2bc)

Sine rule

SinA/a = SinB/b = SinC/c

a/SinA = b/SinB = c/SinC

Area of triangle

Area = 1/2*a*b*SinC

No. of sides and angles

Yes

No

Yes

No

3 sides

1 angle

2 sides

2 angles

2 sides + angle in between