Looking at the worksheet, I need to classify each triangle by both its sides and angles.
First, let me recall the classification system:
- By sides: equilateral (all sides equal), isosceles (two sides equal), scalene (no sides equal)
- By angles: acute (all angles < 90°), right (one angle = 90°), obtuse (one angle > 90°)
Now I'll go through each triangle one by one:
Row 1:
- 1a: Pink triangle - looks like two sides are equal (isosceles) and all angles appear less than 90° (acute) → isosceles acute
- 1b: Green triangle - all sides different (scalene) and one angle appears greater than 90° (obtuse) → scalene obtuse
- 1c: Black triangle - all sides different (scalene) and one angle appears greater than 90° (obtuse) → scalene obtuse
Row 2:
- 2a: Purple triangle - all sides different (scalene) and one angle appears greater than 90° (obtuse) → scalene obtuse
- 2b: Black triangle - looks like two sides equal (isosceles) and all angles less than 90° (acute) → isosceles acute
- 2c: Pink triangle - all sides different (scalene) and one angle appears greater than 90° (obtuse) → scalene obtuse
Row 3:
- 3a: Black triangle - all sides different (scalene) and all angles less than 90° (acute) → scalene acute
- 3b: Teal triangle - all sides different (scalene) and one angle appears greater than 90° (obtuse) → scalene obtuse
- 3c: Pink triangle - all sides different (scalene) and all angles less than 90° (acute) → scalene acute
Row 4:
- 4a: Pink triangle - all sides different (scalene) and all angles less than 90° (acute) → scalene acute
- 4b: Pink triangle - all sides different (scalene) and one angle appears greater than 90° (obtuse) → scalene obtuse
- 4c: Pink triangle - all sides different (scalene) and all angles less than 90° (acute) → scalene acute
Row 5:
- 5a: Purple triangle - all sides different (scalene) and one angle appears greater than 90° (obtuse) → scalene obtuse
- 5b: Green triangle - all sides different (scalene) and all angles less than 90° (acute) → scalene acute
- 5c: Green triangle - all sides different (scalene) and all angles less than 90° (acute) → scalene acute
Let me double-check my work by reviewing a few key ones:
- 1a: Definitely has two equal sides, all angles sharp → isosceles acute ✓
- 1b: Clearly has an obtuse angle, no equal sides → scalene obtuse ✓
- 3a: No equal sides, all angles acute → scalene acute ✓
Final Answer:
1a. isosceles acute
1b. scalene obtuse
1c. scalene obtuse
2a. scalene obtuse
2b. isosceles acute
2c. scalene obtuse
3a. scalene acute
3b. scalene obtuse
3c. scalene acute
4a. scalene acute
4b. scalene obtuse
4c. scalene acute
5a. scalene obtuse
5b. scalene acute
5c. scalene acute
Parent Tip: Review the logic above to help your child master the concept of triangles worksheet 5th grade.
