# Lesson Worksheet: Types of Triangles: Angles and Sides Mathematics • 5th Grade

In this worksheet, we will practice classifying triangles as isosceles, scalene, or equilateral and as acute, right, or obtuse.

Q1:

Which of the following describes the given shape?

• Aobtuse triangle
• Bequilateral triangle
• Cright triangle
• Disoceles triangle
• Eacute triangle

Q2:

Which of the following describes the given shape?

• Aacute isoceles triangle
• Bacute scalene triangle
• Cobtuse isoceles triangle
• Dright scalene triangle
• Eright isoceles triangle

Q3:

Which of the following describes the given shape?

• Aright triangle
• Bisoceles triangle
• Cobtuse triangle
• Dequilateral triangle
• Escalene triangle

Q4:

What do these shapes have in common?

• ABoth are obtuse triangles.
• BBoth are isosceles triangles.
• CBoth are right triangles.
• DBoth are equilateral triangles.
• EBoth are acute triangles.

Q5:

Which of the following describes the given shape?

• Aacute triangle
• Bisoceles triangle
• Cright triangle
• Dobtuse triangle
• Eequilateral triangle

Q6:

Which of the following describes the given shape?

• Aobtuse triangle
• Bright triangle
• Cisoceles triangle
• Dequilateral triangle
• Eacute triangle

Q7:

Which of the following describes the given shape?

• Aright triangle
• Bobtuse triangle
• Cisoceles triangle
• Dequilateral triangle
• Escalene triangle

Q8:

True or False: Some right triangles are isosceles.

• ATrue
• BFalse

Q9:

True or False: Some obtuse triangles are isosceles.

• AFalse
• BTrue

Q10:

True or False: The angles of an equilateral triangle are acute.

• ATrue
• BFalse

Q11:

True or False: The angles of an isosceles triangle are always acute.

• ATrue
• BFalse

Q12:

What do these shapes have in common?

• ABoth are obtuse triangles.
• BBoth are isosceles triangles.
• CBoth are acute triangles.
• DBoth are right triangles.
• EBoth are equilateral triangles.

Q13:

Describe the triangle using an adjective from the list acute, right, obtuse and the list equilateral, isosceles, scalene.

• Aacute equilateral
• Bacute scalene
• Cobtuse scalene
• Dright scalene

Q14:

True or False: All acute triangles are isosceles.

• ATrue
• BFalse

Q15:

If , , and , what is the type of in terms of the measures of its angles?

• Aright-angled triangle
• Bacute-angled triangle
• Cobtuse-angled triangle

Q16:

What do these shapes have in common?

• ABoth are isosceles triangles.
• BBoth are acute triangles.
• CBoth are right triangles.
• DBoth are equilateral triangles.
• EBoth are triangles.

Q17:

Which of the following is true of triangle ?

• AAll its angles are acute.
• BIt is a right-angled triangle.
• CIt has an obtuse angle.

Q18:

What do we call a triangle that has angles , , and ?

• Aan obtuse-angled triangle
• Ban acute-angled triangle
• Ca right-angled triangle

Q19:

One of the base angles of an isosceles triangle is . What type of triangle is this?

• Aobtuse angled
• Bequilateral
• Cright angled
• Dacute angled

Q20:

What do these shapes have in common?

• ABoth are isosceles triangles.
• BBoth are right triangles.
• CBoth are acute triangles.
• DBoth are obtuse triangles.
• EBoth are equilateral triangles.

Q21:

What do these shapes have in common?

• ABoth are isosceles triangles.
• BBoth are right triangles.
• CBoth are equilateral triangles.
• DBoth are acute triangles.
• EBoth are obtuse triangles.

Q22:

Two angles in a triangle are and . What kind of triangle is it, in terms of its angles?

• Aacute-angled
• Bright-angled
• Cobtuse -angled

Q23:

Is a scalene, isosceles, or equilateral triangle?

• Ascalene triangle
• Bequilateral triangle
• Cisosceles triangle

Q24:

What do an obtuse isosceles triangle and a right scalene triangle have in common?

• ABoth have no congruent sides.
• BBoth have two acute angles.
• CBoth have two congruent sides.
• DBoth have no acute angles.

Q25:

Liam cut a 30 cm piece of string into three equal parts. Then, he formed a triangle by using each of the parts as one of the triangleβs sides. Which of these types of triangles did he form?

• AAn acute equilateral triangle
• BA right equilateral triangle
• CAn obtuse equilateral triangle
• DAn acute isosceles triangle
• EA right isosceles triangle