Measuring Angles with a Protractor

The video tutorial covers the concept of measuring angles for fourth-grade students, focusing on Texas standard 4.7c. It uses a problem from the 2019 STAAR test to demonstrate how to measure angles using a protractor. The tutorial explains the types of angles—acute, right, and obtuse—and guides students through solving the problem by subtracting angles to find the correct measurement. The video concludes with the correct answer and a brief explanation.

What is the primary tool used for measuring angles?

• Compass

• Protractor

• Ruler

• Scale

What is the purpose of a protractor in mathematics?

• To measure angles

• To measure distance

• To measure temperature

• To measure weight

What is the vertex of angle RST?

• None of the above

• T

• S

• R

Which letter represents the vertex in angle notation?

• All letters equally

• The last letter

• The middle letter

• The first letter

Which type of angle is less than 90 degrees?

• Straight angle

• Acute angle

• Obtuse angle

• Right angle

What defines a right angle?

• Less than 90 degrees

• None of the above

• More than 90 degrees

• Exactly 90 degrees

If an angle measurement starts at zero, what should you do to find the angle?

• Use the measurement as it is

• Subtract the measurement from 180

• Add 90 to the measurement

• Subtract the measurement from 90

How do you calculate an angle with a non-zero starting point on a protractor?

• None of the above

• Subtract the smaller number from the larger number

• Add the numbers together

• Subtract the larger number from 180

What is the correct angle measurement of RST?

• 130 degrees

• 90 degrees

• 40 degrees

• 80 degrees

What mistake might lead to an incorrect angle measurement of 80 degrees?

• Ignoring the zero start point

• Subtracting incorrectly

• All of the above

• Adding instead of subtracting