Exploring Parallel Lines and Triangle Angles

This video tutorial covers the properties of different types of triangles, including equilateral, isosceles, scalene, right, acute, and obtuse triangles. It explains the triangle angle sum theorem, which states that the sum of the interior angles of a triangle is always 180 degrees. The video provides examples of calculating unknown angles in triangles using this theorem. Additionally, it discusses exterior angles, their supplementary nature, and how they relate to non-adjacent interior angles.

Which type of triangle has all sides and angles congruent?

• Scalene

• Isosceles

• Equilateral

• Right

Tags

CCSS.4.G.A.2

In an isosceles triangle, how many sides and angles are congruent?

• One side and one angle

• No sides and angles

• Two sides and two angles

• All three sides and angles

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

• 360 degrees

• 270 degrees

• 180 degrees

• 90 degrees

Tags

CCSS.8.G.A.5

If a triangle has angles measuring 65 degrees and 57 degrees, what is the measure of the third angle?

• 58 degrees

• 60 degrees

• 57 degrees

• 65 degrees

Tags

CCSS.8.G.A.5

In a right triangle, if one angle is 40 degrees, what is the measure of the other non-right angle?

• 50 degrees

• 60 degrees

• 70 degrees

• 80 degrees

Tags

CCSS.8.G.A.5

What is an exterior angle of a triangle?

• An angle inside the triangle

• An angle formed by extending one side of the triangle

• An angle equal to 90 degrees

• An angle equal to 180 degrees

Exterior angles of a triangle are always supplementary to which angles?

• Adjacent interior angles

• Non-adjacent interior angles

• All interior angles

• None of the above

Tags

CCSS.8.G.A.5

What is the sum of the exterior angles of any polygon?

• 450 degrees

• 360 degrees

• 270 degrees

• 180 degrees

If an exterior angle of a triangle is 110 degrees and one of the non-adjacent interior angles is 80 degrees, what is the measure of the other non-adjacent interior angle?

• 20 degrees

• 30 degrees

• 40 degrees

• 50 degrees

Tags

CCSS.8.G.A.5

If the exterior angle of a triangle is 75 degrees and one of the non-adjacent interior angles is 55 degrees, what is the measure of the other non-adjacent interior angle?

• 30 degrees

• 25 degrees

• 20 degrees

• 35 degrees

Tags

CCSS.8.G.A.5