Classify Triangles by Their Side Lengths

Have protractors ready for the angle page and show how to extend short sides. On the triangle and quadrilateral pages, ask students to say which mark told them the answer.

Classify 9 triangles as scalene, isosceles or equilateral from side lengths like 4 cm, 7 cm, 7 cm. A scalene triangle has no equal sides, an isosceles triangle has at least two equal sides, and an equilateral triangle has three equal sides. The directions on the page read: Use the side lengths or the tick marks. Write scalene, isosceles or equilateral for each triangle. An answer key is included.

Yes, both. We made it for 6th Grade geometry, and the page works the same whether it lands on a kitchen table or a center rotation. At home, most families go through it together and talk the answers out loud, and that talking is where most of the learning happens with classify angles and shapes. In class it runs well as independent work while you pull a small group. Print one copy or thirty, whichever the day needs.

An acute angle is less than 90°, a right angle is exactly 90° and an obtuse angle is between 90° and 180°. On Measure and Classify Angles With a Protractor, a 40° angle is acute and a 135° angle is obtuse.

A scalene triangle has no equal sides, an isosceles triangle has at least two equal sides and an equilateral triangle has three. A triangle with sides 4 cm, 7 cm and 7 cm is isosceles.

It is the name that fits all of its marks. A shape with four right angles and four equal sides is a square, not just a rectangle or a rhombus.

Yes. All 3 sheets have an answer key, and the angle key accepts measures within 2°.