Properties and Types of Triangles

Miss Lee reviews angles and triangles, covering types of angles (acute, right, obtuse, straight) and how to classify triangles by angles and sides (equilateral, isosceles, scalene). The lesson includes practical examples to reinforce understanding.

What is the measure of an acute angle?

• More than 90 degrees

• Exactly 90 degrees

• Exactly 180 degrees

• Less than 90 degrees

Which of the following is true about right angles?

• They measure less than 90 degrees

• They are formed by perpendicular lines

• They form a straight line

• They measure more than 90 degrees

What is a characteristic of congruent angles?

• They form a straight line

• They are always acute

• They have different measures

• They have the same measure

How many acute angles does an acute triangle have?

• None

• Three

• Two

• One

What type of triangle has one right angle?

• Acute triangle

• Obtuse triangle

• Equilateral triangle

• Right triangle

Which triangle has all sides of equal length?

• Scalene triangle

• Isosceles triangle

• Equilateral triangle

• Right triangle

What is a defining feature of an isosceles triangle?

• All angles are equal

• It has a right angle

• Two sides are equal

• All sides are different

In a scalene triangle, how many sides are of different lengths?

• Two

• All

• None

• One

If a triangle has angles measuring 32°, 58°, and 90°, what type of triangle is it?

• Acute scalene

• Right scalene

• Obtuse scalene

• Equilateral

A triangle with angles of 60° each is classified as what?

• Right scalene

• Right isosceles

• Acute equilateral

• Obtuse scalene