4.4 Triangle Angle-Sum Theorem

Theorem- a general proposition not self-evident but proved by a chain of reasoning; a truth established by means of accepted truths.

Match

Match the following

• add up to 180 degrees

• add up to 90 degrees

• are congruent to each other

• have a common side and a common vertex (corner point), and don't overlap.

Supplementary Angles

Complementary Angle

Vertical Angles

Adjacent Angles

• Supplementary Angles

• Complementary Angle

• Vertical Angles

• Adjacent Angles

Match

Match the following

• Three equal sides Three equal angles, always 60°

• Two equal sides Two equal angles

• No equal sides No equal angles

• All angles are less than 90°

• Has an angle more than 90°

Equilateral Triangle

Isosceles Triangles

Scalene Triangles

Acute Triangles

Obtuse Triangles

• Equilateral Triangle

• Isosceles Triangles

• Scalene Triangles

• Acute Triangles

• Obtuse Triangles

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Multiple Choice

According to the Triangle Angle-Sum Theorem, what is the sum of the interior angles of a triangle?

• 180 degrees

• 90 degrees

• 360 degrees

• 270 degrees

Dropdown

The ​

Select answer

of the angles in a triangle are ​

Select answer

degrees

Math Response

A triangle has interior angle measures of

39°, 53°, and x. What is the value of x?

Type answer here

Correct Answer: 88

Deg^°

Rad

Math Response

What is the measure of the missing angle?

Type answer here

Correct Answer: 54

Deg^°

Rad

Math Response

What is the value of p?

Type answer here

Correct Answer: 13

Deg^°

Rad

Math Response

What is the value of a?

Type answer here

Correct Answer: 50

Deg^°

Rad

Multiple Choice

Can you have a triangle with the following angles?

20°, 130°, 40°

• Yes, they equal 180°

• No, they equal 190°

• No, they equal 180°

• Yes, they equal 190°

Multiple Choice

Can you have a triangle with the following angles?

120°, 30°, 30°

• Yes, they equal 180°

• No, they equal 170°

• No, they equal 180°

• Yes, they equal 170°

Multiple Choice

Can you have a triangle with the following angles?

1°, 90°, 90°

• Yes, they equal 180°

• No, they equal 181°

• No, they equal 180°

• Yes, they equal 181°

Multiple Choice

Can you have a triangle with the following angles?

15°, 160°, 5°

• Yes, they equal 180°

• No, they equal 80°

• No, they equal 180°

• Yes, they equal 80°