Classifying Triangles: A Comprehensive Assessment

The video provides a refresher on triangles, covering their classification by angles (acute, right, obtuse) and by side lengths (scalene, isosceles, equilateral). It explains how each triangle can have two names based on these classifications and emphasizes the importance of congruency marks in identifying side lengths. The video concludes with a student activity to apply these concepts.

What defines a polygon as a triangle?

• It is always equilateral.

• It has only acute angles.

• It has three sides and three angles.

• It has four sides.

What type of triangle has all angles less than 90 degrees?

• Right triangle

• Obtuse triangle

• Scalene triangle

• Acute triangle

Which triangle has one angle exactly 90 degrees?

• Obtuse triangle

• Acute triangle

• Isosceles triangle

• Right triangle

A triangle with all sides of different lengths is called?

• Equilateral

• Acute

• Isosceles

• Scalene

What does it mean if a triangle is isosceles?

• It has two equal sides.

• All its sides are of equal length.

• It has one right angle.

• It has no equal sides.

Which triangle cannot exist?

• Scalene obtuse triangle

• Isosceles right triangle

• Scalene right triangle

• Equilateral right triangle

What are congruency marks used for?

• To differentiate obtuse angles

• To mark equal sides

• To show equal angles

• To indicate right angles

An equilateral triangle is also what type of triangle?

• Scalene

• Isosceles

• Right

• Obtuse

Which statement is true about an obtuse triangle?

• It has one obtuse angle and two acute angles.

• It has three obtuse angles.

• It cannot be scalene.

• All its sides are of equal length.

How many names does each triangle have based on classification?

• One

• Two

• Three

• Four