Types of Triangles and Their Properties

The video tutorial introduces triangles as three-sided closed plane figures and explains their symbolic representation. It categorizes triangles into three types: equilateral, isosceles, and scalene, providing detailed explanations and examples for each. The tutorial also includes exercises to identify triangle types based on side lengths, encouraging students to practice on their own.

What is a triangle?

• A three-sided closed plane figure

• A polygon with five sides

• A four-sided figure

• A circle

Which of the following is NOT a type of triangle?

• Isosceles

• Equilateral

• Quadrilateral

• Scalene

In an equilateral triangle, how many sides are of equal length?

• None

• Three

• Two

• One

If a triangle has sides of 5 cm each, what type of triangle is it?

• Right-angled

• Isosceles

• Scalene

• Equilateral

What defines an isosceles triangle?

• It has a right angle

• All sides are different

• At least two sides are equal

• All sides are equal

In triangle ABC, if AB = 7 cm and AC = 7 cm, what type of triangle is it?

• Equilateral

• Scalene

• Isosceles

• Right-angled

Which triangle has all sides of different lengths?

• Right-angled

• Equilateral

• Isosceles

• Scalene

If triangle PQR has sides of 3 cm, 4 cm, and 5 cm, what type of triangle is it?

• Equilateral

• Isosceles

• Scalene

• Right-angled

How can you identify an equilateral triangle from its side lengths?

• All sides are different

• Two sides are equal

• All sides are equal

• It has a right angle

In triangle LMN, if LM = 9 cm, MN = 9 cm, and LN = 9 cm, what type of triangle is it?

• Scalene

• Equilateral

• Right-angled

• Isosceles