Mastering the Triangle Sum Theorem

The video tutorial explains the triangle sum theorem, which states that the sum of the angles in a triangle is always 180 degrees. The instructor demonstrates this theorem using different types of triangles: isosceles, right, and obtuse. Each example involves calculating the sum of the angles to verify the theorem. The tutorial also covers solving for a missing angle in a triangle using inverse operations. The lesson concludes with a final example and a summary of the theorem's proof.

How many degrees are in a full circle?

• 270 degrees

• 180 degrees

• 90 degrees

• 360 degrees

Tags

CCSS.4.MD.C.5B

CCSS.HSG.CO.A.1

What is the sum of the angles in a triangle according to the Triangle Sum Theorem?

• 90 degrees

• 180 degrees

• 360 degrees

• 270 degrees

Tags

CCSS.8.G.A.5

In an isosceles triangle with angles 50°, 65°, and 65°, what is the sum of the angles?

• 160 degrees

• 200 degrees

• 150 degrees

• 180 degrees

Tags

CCSS.8.G.A.5

What is the measure of a right angle?

• 45 degrees

• 120 degrees

• 60 degrees

• 90 degrees

Tags

CCSS.4.G.A.1

In a right triangle with angles 70°, 20°, and 90°, what is the sum of the angles?

• 190 degrees

• 180 degrees

• 170 degrees

• 160 degrees

Tags

CCSS.7.G.B.5

In an obtuse triangle with angles 30°, 110°, and 40°, what is the sum of the angles?

• 160 degrees

• 170 degrees

• 180 degrees

• 190 degrees

Tags

CCSS.8.G.A.5

If a triangle has angles 80°, 52°, and X, what is the value of X?

• 68 degrees

• 38 degrees

• 48 degrees

• 58 degrees

Tags

CCSS.8.G.A.5

In a triangle with a right angle, 35°, and X, what is the value of X?

• 65 degrees

• 55 degrees

• 45 degrees

• 75 degrees

Tags

CCSS.8.G.A.5

What operation is used to solve for a missing angle in a triangle?

• Subtraction

• Division

• Multiplication

• Addition

Tags

CCSS.8.G.A.5

What is the sum of the angles in any triangle?

• 360 degrees

• 270 degrees

• 180 degrees

• 90 degrees

Tags

CCSS.8.G.A.5