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Classifying Shapes

Classify two-dimensional figures based on parallel lines, perpendicular lines, and angles.

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Classifying Shapes

Triangles by Angles

TypeAngles
Acute triangleAll angles less than 90°90°
Right triangleOne angle is exactly 90°90°
Obtuse triangleOne angle is greater than 90°90°

Triangles by Sides

TypeSides
EquilateralAll 3 sides equal
IsoscelesAt least 2 sides equal
ScaleneNo sides equal

Quadrilaterals (4-sided shapes)

ShapeProperties
Parallelogram2 pairs of parallel sides
RectangleParallelogram with 4 right angles
RhombusParallelogram with 4 equal sides
SquareRectangle AND rhombus (4 right angles, 4 equal sides)
TrapezoidExactly 1 pair of parallel sides

Shape Relationships

  • Every square is a rectangle (but not every rectangle is a square)
  • Every square is a rhombus (but not every rhombus is a square)
  • Every rectangle is a parallelogram
  • Every rhombus is a parallelogram

Perimeter

Perimeter = distance around a shape = sum of all sides

  • Rectangle: P=2l+2wP = 2l + 2w
  • Square: P=4sP = 4s

Area

Area = space inside a shape (measured in square units)

  • Rectangle: A=l×wA = l \times w
  • Square: A=s2A = s^2

Remember: Perimeter is measured in units (cm, in). Area is measured in square units (cm², in²).

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Lines, Rays, and Angles

❓ Frequently Asked Questions

What is Classifying Shapes?▾
Classify two-dimensional figures based on parallel lines, perpendicular lines, and angles.
How can I study Classifying Shapes effectively?▾
Start by reading the study notes and working through the examples on this page. Then use the flashcards to test your recall. Regular review and active practice are key to retention.
Is this Classifying Shapes study guide free?▾
Yes — all study notes, flashcards, and practice problems for Classifying Shapes on Study Mondo are free to access. No account is needed.
What course covers Classifying Shapes?▾
Classifying Shapes is part of the Grade 4 Math course on Study Mondo, specifically in the Geometry and Angles section. You can explore the full course for more related topics and practice resources.