Triangle Properties and Theorems

This video tutorial introduces triangles and their properties, including medians, altitudes, and exterior angles. It covers the properties of equilateral, isosceles, and right-angled triangles, and explains the angle sum property and the sum of lengths of sides. The lesson aims to help students understand these concepts and apply them in geometry.

What is a triangle?

• A five-sided polygon

• A two-sided polygon

• A three-sided polygon

• A four-sided polygon

What is a median in a triangle?

• A line segment from a vertex to the opposite side bisecting it

• A line segment from the midpoint of one side to another

• A line segment parallel to one side

• A line segment perpendicular to the base

How many medians does a triangle have?

• Two

• Four

• One

• Three

What is an altitude in a triangle?

• A line segment from a vertex to the opposite side bisecting it

• A line segment perpendicular to the base

• A line segment parallel to one side

• A line segment from the midpoint of one side to another

How many altitudes does a triangle have?

• Two

• Three

• One

• Four

What is an exterior angle of a triangle?

• An angle formed by two medians

• An angle formed by two altitudes

• An angle formed by extending a side of the triangle

• An angle inside the triangle

The measure of an exterior angle of a triangle is equal to:

• The difference between the measures of its interior angles

• The sum of the measures of its adjacent angles

• The sum of the measures of its interior opposite angles

• The product of the measures of its interior angles

What is the angle sum property of a triangle?

• The sum of the measures of the three angles is 360 degrees

• The sum of the measures of the three angles is 270 degrees

• The sum of the measures of the three angles is 180 degrees

• The sum of the measures of the three angles is 90 degrees

What is the sum of the lengths of any two sides of a triangle compared to the third side?

• Sometimes less, sometimes more than the third side

• Always less than the third side

• Always equal to the third side

• Always greater than the third side

What is an equilateral triangle?

• A triangle with one right angle

• A triangle with two sides equal

• A triangle with all sides equal

• A triangle with no sides equal