5th grade classifying triangles worksheets
Fifth grade alternates the two naming systems: half the problems classify by angles (acute, right, obtuse) and half by sides (equilateral, isosceles, scalene). One triangle can hold a name from each family, like a right isosceles triangle.
Free printable PDF worksheet, aligned to Common Core 5.G.B.3.
A new sheet every click.
The kind of problems you'll get
Circle the most specific name for each triangle.
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Circle the kind of triangle.
Answer: obtuse
- Circle the kind of triangle.
- Circle the kind of triangle.
Every print pulls a fresh set of problems at this level, so a make-up test or a second sibling never gets the same sheet.
What's on each sheet
- Fluency. Circle the most specific name for each triangle. 10 questions per page.
Every version prints on US Letter or A4, with its answer key on the last page.
How to teach this
Ask which question the problem is asking first, angles or sides, since the printed choices give it away. For side problems, insist on counting tick marks out loud before answering; eyes are unreliable on close lengths. A good stretch conversation: can a triangle be right and isosceles at the same time? Draw one together and the question settles itself.
Watch for: Kids call a triangle obtuse because it looks big. The classification is about one angle's size, not the whole triangle's. Kids skip the tick marks and eyeball the sides. Equal sides are shown by matching ticks, not by how long the sides look.
Common questions about classifying triangles
- Why do the name choices change from problem to problem?
- The sheet alternates classifying by angles (acute, right, obtuse) with classifying by sides (equilateral, isosceles, scalene). The choices printed with each triangle tell your child which system that problem wants.
- What do the tick marks on the sides mean?
- Sides with matching ticks are equal. All three sides marked equal means equilateral, exactly two means isosceles, and no matches means scalene. The marks are the evidence, not the look of the drawing.
Related worksheets
- 4th grade classifying triangles A step easier, same skill
- 5th grade classifying quadrilaterals Same grade, nearby skill
- 5th grade coordinate plane Same grade, nearby skill
- Classifying triangles, all grades The full progression
- All 5th grade math worksheets Every skill at this level
- All 5th grade worksheets Everything at this level
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Aligned to Common Core 5.G.B.3. Reviewed by the One more sheet curriculum team. Content version 123, updated July 2026.