Formula
- Use the units shown beside each field.
- Results update automatically whenever you change an input.
- Displayed values use up to four decimal places, or scientific notation for very small or large numbers. Calculations use standard floating-point arithmetic; exact integer and fraction tools identify their own precision rules.
- Ideal Euclidean geometry. Use one consistent length unit. Measurements and derived quantities use floating-point arithmetic. Height runs from the apex to the midpoint of the base.
Example Calculation
- Base: 6 units
- Perpendicular height: 4 units
Base 6 and perpendicular height 4 give equal sides 5, area 12 and perimeter 16.
Frequently asked questions
How do I use this calculator?
Enter base, perpendicular height. The result updates automatically. Use Reset to restore the example values.
What method does it use?
equal side=√(height²+(base/2)²); area=base × height/2.. Ideal Euclidean geometry. Use one consistent length unit. Measurements and derived quantities use floating-point arithmetic. Height runs from the apex to the midpoint of the base.
Why might a rounded result differ?
The calculation keeps full numeric precision internally, then rounds the displayed result. Rounding intermediate steps by hand can produce a slightly different answer.
Are my inputs saved online?
No. This calculator processes your inputs in your browser. A recently used list stores only calculator names on this device, not your entered values.
Check the assumptions and units before using this result. Read about calculation methods.