Slant Height Calculator

Calculate slant height for cones, pyramids, and triangles using Pythagorean theorem

Calculate Slant Height

units

Vertical height of the cone

units

Radius of the circular base

Slant Height Results

0.00
Slant Height (l)
0.00
Calculated Radius

Formula used: l = √(h² + r²)

Calculation: l = √(0² + 0²) = 0.00

Shape Analysis

Example Calculation

Right Circular Cone

Given: Height = 12 units, Base radius = 5 units

Formula: l = √(h² + r²)

Calculation: l = √(12² + 5²) = √(144 + 25) = √169 = 13 units

Result: Slant height = 13 units

Right Square Pyramid

Given: Height = 8 units, Base side = 6 units

Formula: l = √(h² + (b/2)²)

Calculation: l = √(8² + 3²) = √(64 + 9) = √73 ≈ 8.54 units

Result: Slant height ≈ 8.54 units

Shape Types

C

Right Circular Cone

l = √(h² + r²)

Uses height and base radius

P

Right Square Pyramid

l = √(h² + (b/2)²)

Uses height and base side length

T

Right Triangle

l = √(h² + b²)

Uses height and base length

Calculation Tips

Slant height is always the hypotenuse of a right triangle

For pyramids, use half the base length in calculations

Elevation angle method uses trigonometry

Slant height is always greater than the height

Understanding Slant Height

What is Slant Height?

Slant height is the distance from the apex (top) of a cone or pyramid to any point on the circumference of the base, measured along the surface. It's the hypotenuse of a right triangle formed by the height and the radius (or half the base length).

Applications

  • Calculating surface area of cones and pyramids
  • Engineering and architectural design
  • Navigation and surveying
  • Angles of elevation calculations

Mathematical Foundation

Pythagorean Theorem: a² + b² = c²

Where c is the slant height (hypotenuse)

Key Formulas

Cone: l = √(h² + r²)
Square Pyramid: l = √(h² + (b/2)²)
Triangle: l = √(h² + b²)
From Angle: l = h / sin(θ)