Presentation on theme: "Perimeter and Area Yr 7 QCA, HBS, Ri. Pin-board shapes Write down the following information for the shape: 1.Count the dots around the perimeter (D.P.)"— Presentation transcript:
Perimeter and Area Yr 7 QCA, HBS, Ri
Pin-board shapes Write down the following information for the shape: 1.Count the dots around the perimeter (D.P.) Draw shapes on the pin-board by joining dots. 2. Count the dots inside the shape (D.I.) 3. Calculate the area of the shape (A.)
Pin-board shapes ShapeAD.I.D.P.Comments No.1104 No No
At home... Conduct your investigation and write down any patterns relating the three variables that you find. Find a formula for the area of a shape using the dots in the perimeter and number of dots in the middle. Give reasons for why your formula works.
Does the number of dots in the perimeter give us the length of the perimeter of the shape?
Who was Pick? Georg Alexander Pick August 10, 1859 – July 26, 1942 Born in Austria, died in Bohemia, now Czech Republic
Teacher only Pick’s Theorem... … is not a relationship about perimeter and area!
Pick’s Theorem What did you discover?
What’s the longest perimeter you can make? Perimeter and area Is there always a relationship between perimeter and area? Draw a shape with area 24, what’s the perimeter of your shape? What’s the smallest area you can make? Draw a shape with perimeter 24, what’s the area of your shape?
Teacher only Activity Ask pupils to investigate rectangles with the perimeter and area in the previous slide using their maths books (squared paper)
Perimeter, area, shapes and designing clothes
Which shapes match? ?
Make your own match In pairs, cut the sleeve of the old t-shirt. In the body of the t-shirt draw a shape that you can ‘sew’ the sleeve into – you cannot chose a circle. What is your guess of how it will look like? If you have time repeat with the other sleeve, with a different shape
Plan your design, draw the shape. Cut out the shape to make a hole. Create your design by stapling the sleeve into your hole.
Perimeter, area, shapes and designing clothes Can you explain your design process? How did you know you would be able to sew the sleeve into the hole? What shape was your hole?