Counting Triangles and Combinations

The video tutorial explains how to count the number of triangles that can be formed from a set of points, excluding degenerate triangles. It covers the process of forming both non-right and right triangles by dividing the points into groups and using combinations to calculate the possible triangles. The tutorial concludes with a total count of 90 triangles.

What type of triangles are excluded from the count?

• Isosceles triangles

• Equilateral triangles

• Right triangles

• Degenerate triangles

Which point must be selected to form a right triangle?

• Any point from the vertical group

• The corner point

• Any point from the horizontal group

• Any point from the diagonal

How are the points divided into groups for counting triangles?

• No grouping is done

• Four groups: one for each point

• Three groups: corner, vertical, and horizontal

• Two groups: vertical and horizontal

What mathematical method is used to count the number of ways to select points?

• Algebra

• Probability

• Combinations

• Permutations

How many points are in the vertical group?

• Six

• Five

• Four

• Three

How many points are in the horizontal group?

• Three

• Four

• Five

• Six

What is the total number of non-right triangles formed by choosing one point from the vertical group and two from the horizontal group?

• 10

• 20

• 30

• 40

How many right triangles can be formed by selecting one point from each group?

• 20

• 10

• 40

• 30

What is the total number of triangles formed, including both right and non-right triangles?

• 60

• 70

• 90

• 80

What is the result of the combination calculation for four choose one?

• 5

• 2

• 3

• 4