This Grade 4 challenge worksheet pushes classification skills further. Students judge whether triangles like right equilateral are possible, classify triangles from given angles, and identify isosceles triangles from side lengths. Fill-in-the-blank items reinforce the 180 degree rule, and hints connect equal angles to equal sides for full triangle descriptions. This Grade 4 worksheet supports classroom practice and homework review at home.
Style:
Classifying Triangles
Part A: Multiple Choice
Circle the best answer for each question.
1. Which triangle is impossible?
A) Right scalene
B) Right equilateral
C) Acute isosceles
D) Obtuse scalene
2. A triangle has angles 25, 65, and 90 degrees. Classify it.
A) Acute scalene
B) Right scalene
C) Right isosceles
D) Obtuse isosceles
3. Which set of side lengths describes an isosceles triangle?
A) 3 cm, 4 cm, 5 cm
B) 5 cm, 5 cm, 5 cm
C) 6 cm, 6 cm, 8 cm
D) 7 cm, 9 cm, 11 cm
4. Two angles of a triangle measure 55 and 55 degrees. What kind of triangle must it be?
A) Right scalene
B) Obtuse isosceles
C) Acute isosceles
D) Equilateral
Part B: Fill in the Blank
Write the correct answer on each line.
1. A triangle has angles 45, 60, and 75 degrees.
2. A triangle has angles 30, 30, and 120 degrees, making it obtuse isosceles.
3. A right triangle with two equal legs has angles of 90, 45, and 45 degrees.
4. If a triangle has angles 70, 70, and 40 degrees, it is an acute isosceles triangle.
5. A triangle with angles 100, 50, and 30 degrees is an obtuse scalene triangle by side lengths.
Classifying Triangles
★ Part A: Multiple Choice
Circle the best answer for each question.
1. Which triangle is impossible?
A) Right scalene
B) Right equilateral
C) Acute isosceles
D) Obtuse scalene
2. A triangle has angles 25, 65, and 90 degrees. Classify it.
A) Acute scalene
B) Right scalene
C) Right isosceles
D) Obtuse isosceles
3. Which set of side lengths describes an isosceles triangle?
A) 3 cm, 4 cm, 5 cm
B) 5 cm, 5 cm, 5 cm
C) 6 cm, 6 cm, 8 cm
D) 7 cm, 9 cm, 11 cm
4. Two angles of a triangle measure 55 and 55 degrees. What kind of triangle must it be?
A) Right scalene
B) Obtuse isosceles
C) Acute isosceles
D) Equilateral
★ Part B: Fill in the Blank
Write the correct answer on each line.
1) A triangle has angles 45, 60, and 75 degrees.
2) A triangle has angles 30, 30, and 120 degrees, making it obtuse isosceles.
3) A right triangle with two equal legs has angles of 90, 45, and 45 degrees.
4) If a triangle has angles 70, 70, and 40 degrees, it is an acute isosceles triangle.
5) A triangle with angles 100, 50, and 30 degrees is an obtuse scalene triangle by side lengths.
Ready to Practice?
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9 Questions
12-18 minutes
Auto-graded
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