Congruent shapes

Congruent shapes have the same size and the same shape.In other words, if you place an object in front of a mirror, the image that you see is congruent or " equal " to the object

When shapes are congruent, all corresponding sides and angles are also congruent.

Look at the following two triangles.You should notice that some sides and some angles have one marking. Others have more than one

Congruent triangles

The side that has one marking corresponds to the other side that also has one marking.

and so forth...

The angle that has one marking corresponds to the other angle that also has one marking.

And so forth...

Having said that the best way to know if two figures are congruent is to compare the corresponding sides and corresponding angles

If these are equal, the figures are congruent. Therefore, be careful when doing your geometry problems about congruence.

Two figures may appear to be congruent yet one side or one angle in one shape may be slightly different than the other shape. Markings on shapes are the best way to compare sides and angles to see if they are equal or congruent

Circles too can be congruent. All circles have congruent angles since a complete turn measures 360 degrees for all circles

Therefore, it is up to the size of the circle and they will have the same size if they have the same radius

Congruent circles
Other examples of congruent shapes or figures

For the quadrilaterals, I used different markings for each side and each angles. Again, corresponding sides and angles have the same amount of markings

For the rectangles, I did not use four different markings although we have four sides. Since opposite sides are equal, I used the same marking for equal sides

The hexagon is a different story. I used the same marking for all angles and sides to keep the figure easy to read. However, at this point, you should be able to recognize corresponding sides and angles without major problems

See also:

congruent triangles
How to use postulates and theorems to check when two triangles are congruent

Similar shapes
Learn to identify when shapes are similar

Similar triangles
Use the angle angle similarity postulate to identify similar triangles

Recent Articles

  1. Least Common Multiple Word Problems

    Mar 22, 18 03:28 PM

    Tease your students or yourself with a variety of least common multiple word problems

    Read More

New math lessons

Your email is safe with us. We will only use it to inform you about new math lessons.

            Follow me on Pinterest

Recent Lessons

  1. Least Common Multiple Word Problems

    Mar 22, 18 03:28 PM

    Tease your students or yourself with a variety of least common multiple word problems

    Read More

  Our Top Pages

Formula for percentage

Compatible numbers

Basic math test

Basic math formulas

Types of angles

Math problem solver

Algebra word problems

Surface area of a cube

Finding the average 

Scale drawings

Tough Algebra Word Problems.

If you can solve these problems with no help, you must be a genius!

Everything you need to prepare for an important exam!

K-12 tests, GED math test, basic math tests, geometry tests, algebra tests. 

Real Life Math Skills

Learn about investing money, budgeting your money, paying taxes, mortgage loans, and even the math involved in playing baseball.


Scientific Notation Quiz

Types of Angles Quiz

Graphing Slope Quiz

Adding and Subtracting Matrices Quiz  

Factoring Trinomials Quiz 

Solving Absolute Value Equations Quiz  

Order of Operations Quiz