1. Identify type of triangle

2. Classification based on angles
1. If each angle of a triangle is an acute angle, it is called an
acute angled triangle.
if one angle is an obtuse angle, then the triangle is called an
obtuse angled triangle.
if any one angle is a right angle, then the triangle is called a
right angled triangle.

3. Classification based on sides
1. If all the three sides of a triangle are equal then it is called an
Equilateral triangle.
2. If any two sides of a triangle are equal then it is called an
isosceles triangle.
3. If all the three sides of a triangle are unequal then it is called a
scalene triangle

4. Classification based on sides given angles
1. If the measure of all angles are different then all sides are different
and therefore is a scalene triangle.
2. If the measure of two angles are equal then two sides are equal
and therefore is a isosceles triangle.
If measures of all three angles are equal then all sides are equal
and therefore is a equilateral triangle.

5. Classification based on sides given angles
1. If the measure of all angles are different then all sides are different
and therefore is a scalene triangle.
2. If the measure of two angles are equal then two sides are equal
and therefore is a isosceles triangle.
If measures of all three angles are equal then all sides are equal
and therefore is a equilateral triangle.

6. Example 1: Identify the triangle if its angles are 30 , 40 and 110
Solution
One angle of the triangle is an obtuse angle(110) , therefore it is an
obtuse angled triangle.
All angles of the triangle are different , therefore it is an scalene triangle.
Example 2: Identify the triangle if its angles are 70 , 50 and 60
Each angle of the triangle is an acute angle , therefore it is an acute angled triangle.

7. Example 3: Identify the triangle if its angles are 45 , 90 and 45
Solution
One angle of the triangle is an right angle(90) , therefore it is an right angled triangle.
Two angles of the triangle are equal , therefore it is an isosceles triangle.
Example 4: Identify the triangle if its angles are 60 , 60 and 60
Each angle of the triangle is an acute angle , therefore it is an acute angled triangle.
All three angles are equal , therefore it is an equilateral triangle.

8. Try these Identify the triangle if its angles are 70 , 40 and 70