Check Similarity in Right Triangles Calculator

Determine if two right triangles are similar and find their scale factor

Check Right Triangle Similarity

First Triangle (enter any 2 sides)

Enter any 2 sides. The third side will be calculated automatically using the Pythagorean theorem.

Second Triangle

The hypotenuse will be calculated automatically from the two legs.

Similarity Analysis

Enter valid triangle measurements to check similarity

Triangle 1: Enter at least 2 sides

Triangle 2: Invalid right triangle

Example: 3-4-5 and 6-8-10 Triangles

Given Triangles:

Triangle 1: sides 3, 4, 5

Triangle 2: sides 6, 8, 10

Similarity Check:

Ratio 1: 6/3 = 2

Ratio 2: 8/4 = 2

Ratio 3: 10/5 = 2

Result: All ratios equal 2, so triangles are similar with scale factor 2

Triangle Similarity Criteria

AA

Angle-Angle

Two corresponding angles equal

SAS

Side-Angle-Side

Two sides proportional, included angle equal

SSS

Side-Side-Side

All corresponding sides proportional

Right Triangle Facts

Right triangles have one 90° angle

Follow Pythagorean theorem: a² + b² = c²

Similar triangles have equal corresponding angles

Proportional sides indicate similarity

Scale factor = ratio of corresponding sides

Understanding Triangle Similarity

What Makes Triangles Similar?

Two triangles are similar if their corresponding angles are equal and their corresponding sides are proportional. For right triangles, since one angle is always 90°, we only need to check if the other angles are equal or if the sides are proportional.

Similarity in Right Triangles

  • If corresponding sides are proportional, triangles are similar
  • The proportionality constant is called the scale factor
  • Similar triangles have identical angle measures
  • Reflections may also create similar triangles

How to Check Similarity

Step-by-Step Process:

  1. 1. Ensure both triangles are valid right triangles
  2. 2. Order the sides from smallest to largest
  3. 3. Calculate ratios of corresponding sides
  4. 4. Check if all ratios are equal
  5. 5. If equal, triangles are similar

Pythagorean Theorem

a² + b² = c²

Where a and b are legs, c is the hypotenuse

Applications of Similar Triangles

Architecture

Scaling blueprints, maintaining proportions in building design

Engineering

Structural analysis, scaling models, stress calculations

Surveying

Measuring distances, height calculations, triangulation