How this calculation works
Find all three perpendicular heights from side lengths.
THE FORMULA
hₐ=2A/a, with area A from Heron’s formulaA worked example
A 3–4–5 triangle has area 6. Its heights are 4, 3 and 2.4.
Good to know
The altitude to a side may meet its extension in an obtuse triangle.
Reference: OpenStax Algebra and Trigonometry, Trigonometric Applications (opens in a new tab) ↗
Read the result
Find all three perpendicular heights from side lengths.
The primary result is labeled “Altitude to side a”. Keep the input definitions in view when comparing this result with another method.
Try a related calculation
The altitude to a side may meet its extension in an obtuse triangle.
For a related exercise, try the circle calculator.
A few questions, answered
How can I check the default inputs by hand?
A 3–4–5 triangle has area 6. Its heights are 4, 3 and 2.4.
Which rule does this calculator apply?
hₐ=2A/a, with area A from Heron’s formula