Mathematics for IGCSE & O level - Mensuration (Section 11 - No. 9)
How is the slant height of a cone related to its radius and height?
Slant height = radius + height
Slant height = √(radius² + height²)
Slant height = √(radius² - height²)
Slant height = radius * height
Explication
The slant height, radius, and height form a right-angled triangle. Using Pythagoras theorem, slant height = √(radius² + height²).