Year 9 Maths Notes

𝐴=𝜋𝑟2

𝐶=2𝜋𝑟

To find arc length or area of a sector, you have to multiply it by the angle (θ) over 360°

Interior + exterior angles add up to 180°

Sum of exterior angles= 360°

Sum of interior angles= 180(n-2)° N= the number of sides

A tessellation is created when a shape is repeated over and over again covering a plane without any gaps or overlaps

Term- An algebraic quantity which only contains letters (and maybe a number)- no signs in the middle!

Expression- Made up of a collection of algebraic terms- no equals sign!

Equation- Contains an equals sign! Can be solved

Formula- A rule linking 2 or more variables. Often a “real life” equation. Starts “letter”=

Inequality- An inequality has the >, <, ≤, ≥

Volume of prisms= area of cross section * length

Graphs can either have positive, negative or no correlation

Pythagoras’ theory= h2=a2+b2 h=hypotenuse a= short side b=short side