Mathematics
Geometry
Procedural
9–10 yrs
Estimating Angles
估算角度
Description
Estimate and compare acute, obtuse, and reflex angles in degrees; classify angles by type and order them by size
Mastery Evidence
- Estimate an angle as approximately 130° and classify it as obtuse
- Identify a reflex angle in a diagram and estimate it as about 270°
- Order four angles from smallest to largest by estimation before measuring
Assessment Prompt
If you show your child three different angles drawn on paper, can they estimate which is biggest, label each as acute, obtuse, or reflex — and then check with a protractor?
Prerequisites 1
Degrees and turns
估算和比较角度需要理解度数系统
Unlocks 1
Regular and irregular polygons
