Triangles by Sides

Quadrilaterals (4-sided shapes)

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: $P = 2l + 2w$
• Square: $P = 4s$

Area

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

• Rectangle: $A = l \times w$
• Square: $A = s^2$

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