This Grade 4 worksheet challenges students with triangle design word problems and reasoning tasks. Learners decide which side and angle combinations form possible triangles and which do not, applying the angle sum rule and side classifications. Multiple choice and fill in the blank items push students to justify why certain triangles cannot exist and to classify triangles using both sides and angles in real design contexts and gardens.
Style:
Classifying Triangles
Part A: Multiple Choice
Circle the best answer for each question.
1. Maya is designing a triangular garden where all three sides must be 8 feet. Which classification fits her garden?
A) Equilateral and acute
B) Isosceles and right
C) Scalene and obtuse
D) Equilateral and obtuse
2. Which set of angles cannot form a triangle?
A) 60, 60, 60
B) 90, 45, 45
C) 100, 50, 40
D) 80, 70, 30
3. A roof truss has two sides of 10 feet and one side of 6 feet. What is its classification by sides?
A) Equilateral
B) Isosceles
C) Scalene
D) Right
4. Can a triangle be both right and obtuse at the same time?
A) Yes, if it has two 90 degree angles
B) Yes, if one angle is 90 and one is 100
C) No, because the angles would sum to more than 180
D) No, because right triangles have no 90 degree angle
Part B: Fill in the Blank
Write the correct answer on each line.
1. If all three sides of a triangular sign are 12 inches, the triangle is classified as equilateral.
2. A triangle with sides 5, 5, 5 has angles that each measure 60 degrees.
3. A set of angles 95, 50, and 35 degrees forms a(n) obtuse triangle.
4. A triangle cannot have two angles each measuring more than 90 degrees at the same time.
5. A triangle with angles 70, 70, and 40 has two equal angles, so its sides also include two congruent sides.
Classifying Triangles
★ Part A: Multiple Choice
Circle the best answer for each question.
1. Maya is designing a triangular garden where all three sides must be 8 feet. Which classification fits her garden?
A) Equilateral and acute
B) Isosceles and right
C) Scalene and obtuse
D) Equilateral and obtuse
2. Which set of angles cannot form a triangle?
A) 60, 60, 60
B) 90, 45, 45
C) 100, 50, 40
D) 80, 70, 30
3. A roof truss has two sides of 10 feet and one side of 6 feet. What is its classification by sides?
A) Equilateral
B) Isosceles
C) Scalene
D) Right
4. Can a triangle be both right and obtuse at the same time?
A) Yes, if it has two 90 degree angles
B) Yes, if one angle is 90 and one is 100
C) No, because the angles would sum to more than 180
D) No, because right triangles have no 90 degree angle
★ Part B: Fill in the Blank
Write the correct answer on each line.
1) If all three sides of a triangular sign are 12 inches, the triangle is classified as equilateral.
2) A triangle with sides 5, 5, 5 has angles that each measure 60 degrees.
3) A set of angles 95, 50, and 35 degrees forms a(n) obtuse triangle.
4) A triangle cannot have two angles each measuring more than 90 degrees at the same time.
5) A triangle with angles 70, 70, and 40 has two equal angles, so its sides also include two congruent sides.
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9 Questions
12-18 minutes
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