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Right Triangle Solver

Special Right Triangle Calculator

30 60 90 Triangle Calculator

Use this 30-60-90 triangle calculator to easily find the short leg, long leg, hypotenuse, area, and perimeter using the exact 30 60 90 triangle formula and ratio.

Find long leg from short leg

This calculator finds Long Leg using long leg = a × √3.

Enter inputs to calculate Long Leg.

All input values must be greater than 0.

Formula

long leg=a×3\text{long leg} = a \times \sqrt{3}
c=2ac = 2a
a=c2a = \frac{c}{2}
a=long leg3a = \frac{\text{long leg}}{\sqrt{3}}
long leg=c×32\text{long leg} = \frac{c \times \sqrt{3}}{2}
Area=short leg×long leg2\text{Area} = \frac{\text{short leg} \times \text{long leg}}{2}
P=short leg+long leg+cP = \text{short leg} + \text{long leg} + c

Triangle Diagram

a a√3 c 30° 60° 90°

Triangle Diagram Key

  • Short leg a is opposite the 30-degree angle.
  • Long leg a√3 is opposite the 60-degree angle.
  • Hypotenuse c is exactly twice the length of the short leg a.

How to Use This Calculator

  1. Select what you want to find from the 30 60 90 calculator modes.
  2. Enter your known side length (short leg, long leg, or hypotenuse).
  3. Verify the number is positive and greater than zero.
  4. Check the result box for your perfectly scaled answer from our 30 60 90 triangle solver.

Step-by-Step Examples

Example 1: Find long leg and hypotenuse when short leg a = 5.

long leg=a×3\text{long leg} = a \times \sqrt{3}
long leg=5×3\text{long leg} = 5 \times \sqrt{3}
long leg8.660\text{long leg} \approx 8.660
c=2ac = 2a
c=2×5c = 2 \times 5
c=10c = 10

Example 2: Find short leg when c = 14.

a=c2a = \frac{c}{2}
a=142a = \frac{14}{2}
a=7a = 7

Example 3: Find long leg from hypotenuse c = 10.

long leg=c×32\text{long leg} = \frac{c \times \sqrt{3}}{2}
long leg=10×32\text{long leg} = \frac{10 \times \sqrt{3}}{2}
long leg=53\text{long leg} = 5\sqrt{3}
long leg8.660\text{long leg} \approx 8.660

What the Result Means

The calculated 30 60 90 triangle sides show exactly how long each part of the triangle needs to be to maintain the 30 and 60 degree angles. They are perfectly proportional.

The 30 60 90 area calculator and 30 60 90 perimeter calculator results give you the exact bounded 2D size and the total outline length of your triangle.

Side Ratio

The standard side ratio for a 30 60 90 triangle is a : a√3 : 2a.

The short leg is a, the long leg is a times the square root of 3, and the hypotenuse is exactly twice the short leg.

When to Use This Calculator

Common Mistakes

help

FAQs

Answers to the most common right-triangle solving questions.

01 How do I use this 30 60 90 triangle calculator? expand_more

Simply choose the value you want to calculate, enter the side you already know, and the tool will use the correct ratio to find the answer.

02 Which side is the short leg and the long leg? expand_more

The short leg is always opposite the 30-degree angle, while the long leg is always opposite the 60-degree angle.

03 What is the formula to find the hypotenuse from the short leg? expand_more

The formula is c = 2a, meaning the hypotenuse is exactly double the length of the short leg.

04 What does the long leg result mean? expand_more

The long leg result tells you the exact height or base required to match the other sides while keeping the 30 and 60 degree angles intact.

05 Can I find the short leg from the long leg? expand_more

Yes, you can find the short leg by dividing the long leg by the square root of 3.

06 Why do we multiply by the square root of 3? expand_more

Multiplying by the square root of 3 is a fixed geometric rule for this triangle type, linking the short leg to the long leg mathematically.

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