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Introduction to Perimeter
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What you will learn from this videoWhat you will learn
- We’ll learn that perimeter is the distance around a shape.
- That we can use perimeter to figure out unknown sides of an object.
- And that knowing the perimeter can help us build a fort, have a party, and even hang our favorite picture.
- Discussion Questions
Before Video
What would you measure with a ruler or yardstick?ANSWERThe length of an object.
The length of a pencil, the length of the room, the length and width of a desk.
Triangle; rectangle, square, parallelogram, or quadrilateral; pentagon; hexagon; octagon.
A 6-sided polygon with all sides the same length. Sample answer: You could measure all 6 sides.
Measure around the outside of the rectangle.
After Video
What are we finding when we measure all of the outside edges around a shape? ANSWERPerimeter.
You can add the given measurement 4 times because all 4 sides of a square are equal. Or you could multiply the known length by 4, since all 4 sides are the same length.
The missing sides are 10 meters and 20 meters.
Add 100 cm eight times; or multiply 8 times 100 cm.
ANSWERThe missing side is 13 cm. "I added the lengths of all sides given, and then subtracted the total from the given perimeter, 58 cm."
- Vocabulary
- Hexagon DEFINE
A 6-sided figure.
- Pentagon DEFINE
A 5-sided figure.
- Polygon DEFINE
A plane figure with at least three straight sides and angles.
- Perimeter DEFINE
The distance around a shape.
- Regular Polygon DEFINE
A polygon that has all sides of equal length and all angles equal.
- Rectangle DEFINE
A 4-sided figure with two pairs of equal sides and four right angles.
- Square DEFINE
A 4-sided shape with 4 sides of equal length and four right angles.
- Hexagon DEFINE
- Reading Material
- Practice Word Problems
- Practice Number Problems
- Lesson Plan
- Teacher Guide
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