Exploring Area and Perimeter of Rectilinear Shapes

Mr. West explains the concepts of area and perimeter using compound shapes. He starts with perimeter, describing it as the total outside length of a shape, and demonstrates how to calculate it by adding the lengths of all sides. He then moves on to area, explaining it as the measure of inside space, and shows how to calculate it by dividing a compound shape into rectangles and summing their areas. The video includes example problems to reinforce understanding.

What is the perimeter of a compound shape?

• Sum of all internal angles

• Sum of all external sides

• Product of length and width

• Sum of the area of individual shapes

How can missing lengths in a compound shape be determined?

• By estimation

• Through addition or subtraction

• Cannot be determined

• Using a ruler

What does the perimeter of a shape represent?

• Total area inside the shape

• Total distance around the shape

• Number of sides the shape has

• Length of the longest side

How do you calculate the area of a compound shape?

• Adding the area of simpler shapes it's divided into

• Multiplying the perimeter by two

• Adding the perimeter of all individual shapes

• Multiplying the longest side by two

What is the formula to calculate the area of a rectangle?

• Length x Width

• (Length + Width) / 2

• 2 x (Length + Width)

• Length + Width

Why is it important to divide compound shapes into simpler shapes when calculating area?

• To use more mathematical formulas

• To increase the total area

• Because it's easier to find the area of simpler shapes

• To make the calculation more complex

What is the area of a rectangle with a length of 5cm and width of 3cm?

• 8cm squared

• 8cm

• 15cm squared

• 15cm

What is the first step in calculating the perimeter of a new shape?

• Finding the missing side lengths

• Adding all the visible sides

• Dividing it into simpler shapes

• Multiplying the length by the width

How do you approach calculating the perimeter of a shape with missing sides?

• Ignore the missing sides

• Estimate the length of missing sides

• Calculate the lengths using other known lengths

• Only add the lengths of visible sides

How do you find the area of a shape with a missing chunk?

• Guess the missing area

• Divide it into complete rectangles and sum their areas

• Multiply the visible sides

• Subtract the missing area from the total