Convex and Concave Polygons

We will learn about the convex and concave polygons and their properties.

Convex polygon:

If each of the interior angles of a polygon is less than 180°, then it is called convex polygon.

Note: In this type of polygon, no portion of the diagonals lies in the exterior.


Examples of convex polygons:

In the adjoining figure of a parallelogram there are four interior angles i.e., ∠BAD, ∠ADC, ∠DCB and ∠CBA. None of the four interior angles is greater than equal to 180° and no portion of the diagonals lies in the exterior.

Convex Polygon Parallelogram

In the adjoining figure of a rectangle there are four interior angles i.e., ∠CBA, ∠DCB, ∠ADC and ∠BAD. None of the four interior angles is greater than equal to 180°.

Convex Polygon Rectangle


In the adjoining figure of a pentagon there are five interior angles i.e., ∠ABC, ∠BCD, ∠CDE, ∠DEA and ∠EAB. None of the five interior angles is greater than equal to 180°.

Convex Polygon Pentagon


In the adjoining figure of a triangle there are three interior angles i.e., ∠ABC, ∠BCA, and ∠CAB. None of the three interior angles is greater than equal to 180°.

Convex Polygon Triangle


Concave polygon:

If at least one angle of a polygon is more than 180°, then it is called a concave polygon.


Examples of concave polygons:

In the adjoining figure of a hexagon there are six interior angles i.e., ∠ABC, ∠BCD, ∠CDE, ∠DEF, ∠EFA and ∠FAB.  Among the six interior angles, ∠CDE is greater than 180°.

Concave Polygon Hexagon


In the adjoining figure of a septagon there are seven interior angles i.e., ∠ABC, ∠BCD, ∠CDE, ∠DEF, ∠EFG, ∠FGA and ∠GAB.  Among the seven interior angles, ∠DEF is greater than 180°.

Concave Polygon Septagon


In the adjoining figure of a quadrilateral there are four interior angles i.e., ∠ABC, ∠BCD, ∠CDA and ∠DAB.  Among the four interior angles, ∠BCD is greater than 180°.

Concave Polygon Quadrilateral

Note: In this type of polygon, some portion of the diagonals lies in the exterior of the polygon.

In the above quadrilateral the portion of the diagonal AC i.e., CE lies in the exterior ∠BCD.

Polygons

Polygon and its Classification

Terms Related to Polygons

Interior and Exterior of the Polygon

Convex and Concave Polygons

Regular and Irregular Polygon

Number of Triangles Contained in a Polygon

Angle Sum Property of a Polygon

Problems on Angle Sum Property of a Polygon

Sum of the Interior Angles of a Polygon

Sum of the Exterior Angles of a Polygon






7th Grade Math Problems 

8th Grade Math Practice 

From Convex and Concave Polygons to HOME PAGE




Didn't find what you were looking for? Or want to know more information about Math Only Math. Use this Google Search to find what you need.



New! Comments

Have your say about what you just read! Leave me a comment in the box below. Ask a Question or Answer a Question.

Share this page: What’s this?

Recent Articles

  1. Place Value | Place, Place Value and Face Value | Grouping the Digits

    Oct 04, 24 09:47 AM

    Place Value of 3-Digit Numbers
    The place value of a digit in a number is the value it holds to be at the place in the number. We know about the place value and face value of a digit and we will learn about it in details. We know th…

    Read More

  2. Worksheet on Subtraction | Practice the Questions | Free Answers

    Oct 04, 24 01:28 AM

    In worksheet on subtraction, all grade students can practice the questions on subtracting numbers with more than two digits. This exercise sheet on subtraction can be practiced by the students

    Read More

  3. Subtraction Word Problems - 2-Digit Numbers | Subtraction Problems

    Oct 03, 24 03:22 PM

    Understand the concept on subtraction word problems - 2-digit numbers for the second grade. Read the question carefully to subtract the two-digit numbers to find the differences and follow the

    Read More

  4. Worksheet on Checking Subtraction Using Addition | Free Answers | Math

    Oct 03, 24 02:22 PM

    Checking Subtraction using Addition
    Here we can use addition to check the answer for the subtraction. Subtract ans check your answer. Find the difference and check your answer using addition.

    Read More

  5. Check for Subtraction and Addition | Checking Subtraction | Problems

    Oct 03, 24 01:13 PM

    Checking Subtraction with Addition
    We will learn to check for subtraction and addition answers after solving. Difference of two numbers is correct when the sum of the subtrahend number and the difference is equal to the minuend.

    Read More

Polygons - Worksheets

Worksheet on Polygon and its Classification

Worksheet on Interior Angles of a Polygon

Worksheet on Exterior Angles of a Polygon