IGCSE Maths formulas A–Z

A–Z

A

• Arc length arc length = θ/360 × 2πr
• Area of a sector area = θ/360 × πr²
• Area of a trapezium A = ½(a + b)h
• Area of a triangle (½ab sin C) Area = ½ab sin C

C

• Compound interest A = P(1 + r/100)ⁿ
• Cosine rule a² = b² + c² − 2bc cos A

D

• Distance formula (length of a line segment) d = √((x₁ − x₂)² + (y₁ − y₂)²)

G

• Gradient formula m = (y₂ − y₁) / (x₂ − x₁)

I

• Interior angles of a polygon (n − 2) × 180°

M

• Midpoint formula M = ((x₁ + x₂)/2, (y₁ + y₂)/2)

P

• Percentage change (new − original) / original × 100
• Probability formulas P(not A) = 1 − P(A)
• Pythagoras' theorem a² + b² = c²

Q

• Quadratic formula x = (−b ± √(b² − 4ac)) / 2a

S

• Simple interest I = Prn / 100
• Sine rule a/sin A = b/sin B
• SOH CAH TOA (right-angled trigonometry) sin = opp/hyp, cos = adj/hyp, tan = opp/adj
• Speed, distance and time speed = distance ÷ time

V

• Volume of a cone V = ⅓πr²h
• Volume of a sphere V = ⁴⁄₃πr³

By topic

Algebra

Quadratic formula

Number and finance

Compound interestPercentage changeSimple interestSpeed, distance and time

Geometry and trigonometry

Arc lengthArea of a sectorArea of a triangleCosine rulePythagoras' theoremSine ruleSOH CAH TOA

Coordinate geometry

Distance formulaGradient formulaMidpoint formula

Mensuration

Area of a trapeziumInterior angles of a polygonVolume of a coneVolume of a sphere

Statistics and probability

Probability formulas