Exploring Angles: Measure and Classify

Grade 8 Mathematics 30-minute interactive lesson I can identify, measure, and classify angles

Classroom Angle Hunt

Find 3 angles around the classroom Use your protractor to measure each angle Record measurements on your worksheet Estimate: Is it acute, right, or obtuse? Time limit: 3 minutes

What Are Angles?

An angle is formed by two rays meeting at a point The meeting point is called the vertex Angles are measured in degrees (°) We use protractors to measure angles accurately

Types of Angles Classification Chart

Acute Angles

Measure less than 90 degrees Sharp and pointed Examples: slice of pizza, bird's beak Think 'a-cute' = small and sharp

Right Angles

Measure exactly 90 degrees Form perfect square corners Examples: book corners, door frames Look for the small square symbol

Obtuse Angles

Measure more than 90° but less than 180° Wide and open Examples: laptop screen when open, reclining chair Think 'obtuse' = big and wide

Pair Angle Classification

Work with your partner Sort angle flashcards into three groups Measure each angle with your protractor Discuss why each angle belongs in its group Use the classification chart to check your work

Success Check: Can You Classify?

Look at the angle on your worksheet Measure it with your protractor Is it acute, right, or obtuse? Explain your reasoning using geometry vocabulary