Finding Missing Angles in Triangles

The video tutorial explains how to find a missing angle in a triangle using the triangle sum theorem. It begins by setting up the equation that the sum of the internal angles equals 180 degrees. The tutorial then demonstrates substituting given values into the equation and solving for the variable x. Finally, it calculates the measure of each angle in the triangle using the solved value of x.

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

• 90 degrees

• 180 degrees

• 270 degrees

• 360 degrees

Tags

CCSS.8.G.A.5

If angle A is 2x, angle B is 2x + 10, and angle C is 94 degrees, what is the general equation for the sum of the angles?

• 2x + 2x + 10 + 94 = 360

• 2x + 2x + 10 + 94 = 90

• 2x + 2x + 10 + 94 = 180

• 2x + 2x + 10 + 94 = 270

What is the first step in solving for x after substituting the given angles into the equation?

• Subtract 104 from each side

• Add 104 to each side

• Divide both sides by 4

• Combine like terms

Tags

CCSS.8.G.A.5

After combining like terms, what is the resulting equation before solving for x?

• 4x - 104 = 360

• 4x + 104 = 360

• 4x - 104 = 180

• 4x + 104 = 180

Tags

CCSS.8.G.A.5

What is the value of x after solving the equation 4x + 104 = 180?

• 94

• 48

• 38

• 19

What is the measure of angle A if x is 19?

• 94 degrees

• 48 degrees

• 38 degrees

• 19 degrees

Tags

CCSS.7.G.B.5

What is the measure of angle B if x is 19?

• 48 degrees

• 94 degrees

• 38 degrees

• 19 degrees

Tags

CCSS.7.G.B.5