# SSS Similarity

How to use the SSS similarity to show that the given triangles are similar: postulate, 1 example, and its solution.

## Postulate

For two triangles,

if three sides of each triangle are proportional

(a/a' = b/b' = c/c'),

then those two triangles are similar.

This is the SSS similarity postulate.

(Side-Side-Side similarity)

## Example

Solution

Solution (Detail)

Draw △ABD.

Draw △DCB.

Make the shape of △DCB

the same as △ABD.

Use these two triangles

to show that △ABD and △DCB are similar.

Find the ratios of each corresponding sides.

6/3 = 2

4/2 = 2

8/4 = 2

6/3 = 2

4/2 = 2

8/4 = 2

So 6/3 = 4/2 = 8/4.

Three sides of each triangle are proportional:

6/3 = 4/2 = 8/4.

Then, by the SSS similarity postulate,

△ABD and △DCB are similar.

This is the proof of the example.