Calculating Perimeter and Area

Study Notes

Perimeter is the total distance around the outside of a two-dimensional shape.
To calculate the perimeter, add the lengths of all the sides.
Units for perimeter are always linear, such as centimeters, meters, or kilometers.

Calculating Perimeter for Different Shapes

Rectangle: Perimeter = 2 × (length + width)
Square: Perimeter = 4 × side length
Triangle: Perimeter = side 1 + side 2 + side 3
Circle (Circumference): Circumference = 2 × π × radius, or Circumference = π × diameter
- π (pi) is approximately 3.14159

Area

Area is the amount of space inside a two-dimensional shape.
Units for area are always expressed as squares, such as square centimeters (cm²), square meters (m²), or square kilometers (km²).

Calculating Area for Different Shapes

Rectangle: Area = length × width
Square: Area = side length × side length
Triangle: Area = ½ × base × height
Circle: Area =π × radius²
Parallelogram: Area = base × height
Trapezium: Area = ½ × (sum of parallel sides) × height

Key Considerations

For irregular shapes, sometimes it is necessary to divide the shape into simpler shapes, calculate the area of each, and then add the individual areas together.
Carefully consider the units when calculating and reporting perimeter and area. Ensure consistency – all lengths must use the same unit.
Accurate measurements are crucial for accurate calculations of both perimeter and area.
Be precise when labelling units in calculations and answers.
Understanding geometrical theorems or formulas is essential to solve problems.

Description

Test your understanding of how to calculate perimeter and area for various geometric shapes. This quiz covers formulas for rectangles, squares, triangles, and circles, along with definitions and unit measurements. Perfect for students learning geometry concepts in class.