Page 2 - Estimating angles
P. 2
o 0°: No angle, rays overlap (e.g., open door closed completely).
o 45°: Half of a right angle. It’s often seen in things like triangular
pieces or wedges.
o 90°: Right angle, like the corner of a book, or where two
perpendicular lines meet.
o 120°: A slightly open angle, wider than 90°.
o 180°: Straight line, two rays going in opposite directions.
o 360°: A full circle, like the hands of a clock making one complete
rotation.
2. Compare with Familiar Objects:
Use objects around you to relate the size of an angle. For example:
o The corner of a book is a right angle (90°).
o A small wedge (like a pizza slice) is often close to 45°.
o A door slightly ajar might be close to 30°.
3. Consider Symmetry:
Symmetrical objects, like squares or rectangles, can help you compare
angles. For example, the corners of these shapes are 90° angles, so
anything larger or smaller can be compared to that.
Learning Outcomes:
By the end of the lesson, students will be able to:
1. Understand the concept of estimating angles without using a protractor.
2. Identify and recognize key reference angles such as 0°, 45°, 90°, 120°,
and 180°.
3. Estimate the size of various angles in real-life situations based on visual
cues and reference angles.
4. Use strategies such as the clock method, quarter turns, and visual
comparisons to estimate angles accurately.
5. Draw and label estimated angles based on their guesses and check them
against actual measurements.
