Let me work through each angle in the worksheet carefully.
Looking at the 9 angles to classify:
Row 1:
1. First angle (top-left): This shows a right angle - two lines meeting at what appears to be exactly 90 degrees, with a small square/arc indicator. This is a
Right angle (= 90°).
2. Second angle (top-middle): This shows an acute angle - the opening is narrow, clearly less than 90°. This is an
Acute angle (< 90°).
3. Third angle (top-right): This shows an obtuse angle - the opening is wide, greater than 90° but less than 180°. This is an
Obtuse angle (> 90°).
Row 2:
4. Fourth angle (middle-left): This shows a reflex angle - the arc goes around more than half way, indicating it's greater than 180°. This is a
Reflex angle (> 180°).
5. Fifth angle (middle-center): This shows a right angle - the lines form an L-shape with a square corner indicator. This is a
Right angle (= 90°).
6. Sixth angle (middle-right): This shows an acute angle - narrow opening, less than 90°. This is an
Acute angle (< 90°).
Row 3:
7. Seventh angle (bottom-left): This shows a straight angle - the line is flat, forming 180°. This is a
Straight angle (= 180°).
8. Eighth angle (bottom-center): This shows a reflex angle - the arc wraps around showing more than 180°. This is a
Reflex angle (> 180°).
9. Ninth angle (bottom-right): This shows an obtuse angle - wider than 90° but not straight. This is an
Obtuse angle (> 90°).
Let me verify my classifications by checking the visual indicators again:
- Right angles have the small square marker at the vertex
- Acute angles are narrow (< 90°)
- Obtuse angles are wide but not straight (> 90°, < 180°)
- Straight angles form a straight line (180°)
- Reflex angles have arcs that go more than halfway around (> 180°)
My final answers:
1. Right
2. Acute
3. Obtuse
4. Reflex
5. Right
6. Acute
7. Straight
8. Reflex
9. Obtuse
Parent Tip: Review the logic above to help your child master the concept of 4th grade angles worksheet.
