Triangle Properties and Angle Measures

Brandon Gley, a high school math teacher, reviews basic triangle features, including the angle sum property. He explains how to classify triangles by their angles (acute, right, obtuse) and by their sides (scalene, isosceles, equilateral). The video also covers solving for unknown angles in triangles and introduces Greek letters commonly used in geometry. The session concludes with a recap of the key concepts discussed.

What is the sum of the interior angles of a triangle?

• 360 degrees

• 180 degrees

• 270 degrees

• 90 degrees

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

• Scalene triangle

• Obtuse triangle

• Right triangle

• Acute triangle

A triangle with one angle exactly 90 degrees is called a:

• Equilateral triangle

• Right triangle

• Acute triangle

• Obtuse triangle

Which triangle has one angle greater than 90 degrees?

• Acute triangle

• Isosceles triangle

• Right triangle

• Obtuse triangle

What is a scalene triangle?

• One angle is 90 degrees

• All sides and angles are equal

• Two sides and angles are equal

• All sides and angles are different

In an isosceles triangle, how many sides are equal?

• Two

• One

• None

• Three

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

• 30 degrees

• 90 degrees

• 45 degrees

• 60 degrees

If two angles of a triangle are 51° and 90°, what is the third angle?

• 90°

• 45°

• 60°

• 39°

In an isosceles triangle with one angle of 120°, what is the measure of the other two angles?

• 90°

• 45°

• 30°

• 60°

Which Greek letter is commonly used to represent angles in mathematics?

• Alpha

• Beta

• Gamma

• Theta