Classification of Triangles
Do you remember a polygon with the least number of sides? That is a
Let us see the different types of triangles we can get.
Naming triangles based on sides
A triangle having all three unequal sides is called a
Three unequal Sides: AB, BC , CA
A triangle having two equal sides is called an
Two equal Sides: DE, FD
A triangle having three equal sides is called an
Three equal Sides: XYZ
A triangle having all three unequal sides is called a Scalene Triangle.
A triangle having two equal sides is called an Isosceles Triangle.
A triangle having three equal sides is called an Equilateral Triangle.
Naming triangles based on angles
Name of the triangle:
Name of the triangle:
Name of the triangle:
If each angle is less than 90°, then the triangle is called an acute angled triangle.
If any one angle is a right angle then the triangle is called a right angled triangle.
If any one angle is greater than 90°, then the triangle is called an obtuse angled triangle.
Let's carry out an activity : you can move the vertices
Do you observe anything? Some of the facts that you may have noticed may include that:
You can move around vertices A,B,C and observe the change in angle measure.
All unequal Sides: AB, BC , CA
When a triangle has all the equal angles, then its sides are also
.
+ Also if a triangles has all the three sides as equal, then its angles are also
+ If two sides of a triangle are equal, then it also has
+ If the three sides of a triangle are unequal then the three angles are also
Let's Solve
1. Match the following :
2. Name each of the following triangles in two different ways: (you may judge the nature of the angle by observation)