Circles (Edexcel GCSE Maths): Flashcards

Distance from centre to edge; half the diameter

Distance across through centre; twice the radius

Distance around the edge (perimeter of circle)

Diameter = 2 × radius

$C = \pi d$

$C = 2\pi r$

3.142

Special mathematical constant ≈ 3.141592...

Diameter is given

Radius is given

Don't round until end to prevent errors

Use π button (may need SHIFT)

Units are correct (cm, m, etc.)