Types and Properties of Triangles

This video tutorial covers angle relationships and similar triangles, focusing on the triangle sum theorem and classifying triangles by their sides and angles. It explains the triangle sum theorem, demonstrates how to find missing angles, and describes different types of triangles based on side lengths and angle measures. The tutorial includes examples to reinforce the concepts of scalene, isosceles, equilateral, acute, right, obtuse, and equiangular triangles.

What is the sum of the angles in any triangle?

• 180°

• 90°

• 360°

• 270°

If two angles of a triangle are 70° and 80°, what is the measure of the third angle?

• 30°

• 20°

• 50°

• 40°

Which type of triangle has all sides of different lengths?

• Equilateral

• Right

• Isosceles

• Scalene

What is a triangle called if it has two equal sides?

• Isosceles

• Scalene

• Equilateral

• Right

Which type of triangle has all angles less than 90°?

• Right

• Obtuse

• Acute

• Equiangular

What is the name of a triangle with one angle measuring 90°?

• Equiangular

• Acute

• Right

• Obtuse

If a triangle has one obtuse angle, what are the other two angles?

• Obtuse

• Acute

• Right

• Equiangular

What is the measure of each angle in an equiangular triangle?

• 45°

• 30°

• 90°

• 60°

What do you call a triangle with all sides and angles equal?

• Right

• Equilateral

• Scalene

• Isosceles

Which type of triangle is both isosceles and has an obtuse angle?

• Isosceles obtuse

• Isosceles right

• Equilateral

• Scalene obtuse