Finding the Perimeter and Area of a Composite Shape | L-Shaped Example | Geometry | Math with Mr. J

Main Ideas and Concepts:

• Perimeter:
  • The Perimeter is defined as the distance around the outside of a shape.
  • To find the Perimeter, all side lengths must be added together.
  • Missing side lengths can be determined using known measurements.
• Area:
  • Area is the amount of space or surface inside a shape.
  • For composite shapes, the Area can be calculated by dividing the shape into simpler shapes (rectangles, triangles, etc.), finding their individual areas, and then summing them.

Methodology for Finding Perimeter:

• Identify any missing side lengths.
• Use known dimensions to calculate missing sides:
  • For vertical sides, ensure they sum up to the known total.
  • For horizontal sides, use the lengths of the segments to find the total Length.
• Add all side lengths together to calculate the Perimeter:
  • Example calculation: 6 + 11 + 14 + 4 + 8 + 7 = 50 feet
• Final Perimeter: 50 feet

Methodology for Finding Area:

1. Separate the Composite Shape:
   • Divide the L-shaped figure into two rectangles (labeled A and B).
2. Calculate Area of Rectangle A:
   • Use the formula: Area = Length × Width
   • For Rectangle A (7 feet by 6 feet):
     • Area = 7 × 6 = 42 square feet
3. Calculate Area of Rectangle B:
   • For Rectangle B (14 feet by 4 feet):
     • Area = 14 × 4 = 56 square feet
4. Sum the Areas:
   • Total Area = Area of A + Area of B
   • Total Area = 42 + 56 = 98 square feet

Final Results:

• Perimeter: 50 feet
• Total Area: 98 square feet

Speakers or Sources Featured:

• Mr. J (the primary speaker and educator in the video)