Surface area (Edexcel GCSE Maths): Flashcards

Total area of all outer surfaces of a 3D shape

$\pi rl$

Slant height (apex to edge of base)

$\pi r^2 + \pi rl$

Use Pythagoras' theorem

$l^2 = h^2 + r^2$

$4\pi r^2$

$2\pi r^2$

$3\pi r^2$

Count external surfaces only, not internal

Base area + curved surface area

4 times area of great circle ($\pi r^2$)

Confusing vertical height with slant height