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2-D shapes: sides and vertices평면도형의 이름: 변과 꼭짓점

Straight or curved? Count the sides, then name the shape. Turn it around. Same shape, same name!

Step 1워크북 2쪽 →
한국어 요약

빨대(변)와 점토 공(꼭짓점)으로 삼각형·정사각형·직사각형·오각형·육각형을 만들고, 만든 뒤에 side와 vertex라는 이름을 붙이는 순서를 영어로 가르쳐요. 돌려 놓은 정사각형도 정사각형이라는 것, 정사각형은 특별한 직사각형이라는 것, 비뚤어진 오각형·길쭉한 육각형도 같은 이름이라는 것을 대본과 놀이로 담았어요.

이 주제의 단어sidepentagonhexagon
이 주제 차례 (8)

The big idea핵심

A 2-D shape is flat. Its outline is made of straight lines, curved lines, or both. A circle is curved all the way round. Its outline has no straight parts.

Each straight line of a shape is a side. A point where two sides meet is a vertex. One vertex, three vertices. Lia may say “corner”. In maths, a corner is a vertex.

Make it first, then give the name. After Lia joins three straws, say: “Each straw is a side.” After she counts five sides, say: “Five sides make a pentagon.”

The name comes from the sides and vertices, not from the way the shape sits. A turned square is still a square. A long, thin hexagon is still a hexagon. Turn it around. Same shape, same name!

A square is a special rectangle. Both have 4 sides and 4 square corners. In a square, all the sides are the same length.

Get ready준비물

  • Drinking straws: some long, some cut shorter
  • Play dough (small balls for the vertices)
  • A piece of string
  • A tray or a plate you can turn
  • Paper and a pencil

Teach it, step by step단계별 수업

YOU 부모가 할 말CHILD 아이가 할 만한 대답DO 손으로 할 일

Straight or curved?

DOPut a straw and a piece of string side by side.
CHILDThe straw is straight. The string is curved!
YOU“Join the ends of the curved string.”
CHILDIt's a circle! Curved all the way round.
YOU“A circle's outline has no straight parts.”

Sides and vertices

YOU“Join three straws with play dough.”
CHILDThree straight straws. I made a triangle!
YOU“Each straw is a side.”
CHILDA triangle has three sides! The play dough is at the corners.
YOU“In maths, a corner is a vertex. One vertex. Three vertices.”
CHILDThree sides, three vertices. A triangle!

Let Lia make the shape before you give the name. Experience first, name after. Say “corner is a vertex” once, as a bridge. After that, say vertex.

Square and rectangle: turn it around

DOGive Lia four straws, all the same length.
CHILDFour sides, all the same. It's a square! Four vertices. Four square corners.
DONow give her two long straws and two short straws.
CHILDTwo long sides, two short sides. A rectangle!
YOU“A square is a special rectangle.”
DOPut the square on a tray. Turn the tray, so a vertex points up.
YOU“Now it's a diamond. Not a square!”
CHILDWait! Four sides, all the same length. Four square corners. It's still a square!
YOU“Oh! I only turned it. Still a square.”
CHILDTurn it around. Same shape, same name!

Make this mistake on purpose, once. Lia proves it with the sides and the square corners. Turn the tray back only after that, as a check. Say “A square is a special rectangle” once, and never “It’s not a rectangle, it’s a square.”

Pentagon and hexagon

DOMake a house shape: three straws for the house, two for the roof.
YOU“How many sides?”
CHILDThree for the house, two for the roof. Five sides!
YOU“Five sides make a pentagon.”
DOMake a second pentagon with five straws, all the same length.
CHILDDifferent, but still a pentagon!
DOLet Lia make a shape with six straws. Then squash it long and thin.
YOU“Six sides make a hexagon.”
CHILDThree on top, three on the bottom. Six sides! Long, but still a hexagon!

Point to the sides in groups (three and two, three and three), not one by one.

Name it and say why

DOPut a long rectangle down at a slant.
YOU“What shape is this?”
CHILDThe question is: what shape is this?
CHILDFirst I look at the sides and the square corners.
CHILDSo it is a rectangle.
CHILDI know because it has four sides and four square corners.

The reason is always about the sides and the vertices. “It is only tilted” is true, but it is not the reason.

광고

Other ways to say it다른 표현

  • “What shape is this?”
  • “Name the shape.”
  • “How many sides does it have?”
  • “How many vertices? How many corners?”
  • “Which one is a hexagon?”
  • “Turn it around. Same shape, same name!”
  • “Count them, then name it!”

Worksheet English표현

  • “Name the 2-D shapes.”
  • “How many sides and vertices does each shape have?”
  • “Circle the shapes with 4 sides.”
  • “Tick the triangles.”
  • “Is this a pentagon? How do you know?”

Good questions to ask좋은 질문

  • “Straight or curved?”

    Good answers

    “The straw is straight. The string is curved.”

  • “How many sides? How many vertices?”

    Note

    For a shape with straight sides, the two numbers are the same: 5 sides, 5 vertices.

  • “I turned it. Is it still a square? How do you know?”

    Good answers

    “Yes. Four sides, all the same length. Four square corners.”

  • “Is a square a rectangle?”

    Note

    Yes. A square is a special rectangle: 4 sides and 4 square corners, and all the sides are the same length.

  • “Can a pentagon look different?”

    Good answers

    “Yes! Any shape with five straight sides is a pentagon.”

If Lia is stuck막힐 때

  • When

    She says a turned square is “a diamond, not a square”.

    “Diamond” is a fine everyday word. The mistake is “not a square”. Look at the sides and square corners together: four the same, four square corners. “Turn it around. Same shape, same name!”

  • When

    She says a long, thin hexagon or a house-shaped pentagon has the wrong name.

    Look at the sides in groups: three on top, three on the bottom. Six straight sides make a hexagon, long or short.

  • When

    She says “It’s not a rectangle, it’s a square.”

    “A square is a special rectangle.” Both have 4 sides and 4 square corners.

  • When

    She calls a shape with one curved side a triangle (like a slice of pizza).

    Run a finger along the curved side. “A triangle has three straight sides. This one is curved.”

  • When

    She counts the same vertex twice.

    Put a small dot on the vertex where she starts. Stop when she comes back to the dot.

  • When

    She says “corners” or “points”.

    Good thinking! Then give the maths name once: “In maths, a corner is a vertex.”

Games (2)놀이

Game · Straw shapes

You need: straws (some cut shorter), play dough

  1. Take turns. One person calls a number from 3 to 6: “Five!”
  2. The other makes a shape with that many straws. Any lengths, any shape.
  3. Name it together: “Five sides, five vertices. A pentagon!”
  4. Make one mistake on purpose: turn a square and say it is “not a square”. Can she catch it?
Game · Shape spotting

You need: nothing — look around the house

  1. Look for flat shapes: stickers, pictures in books, flags on a card.
  2. Name each one and say why: “A hexagon. I know because it has six straight sides.”
  3. Find one that is upside down or stretched. Is it still the same shape?
Next in class

After these steps, the class draws 2-D shapes, finds lines of symmetry and sorts shapes. The school teaches these. Knowing side and vertex makes those lessons easier.

In the workbook

Shape words, and how many sides and vertices each shape has.

워크북 2쪽 보기이 주제 인쇄

자주 묻는 질문

꼭짓점은 영어로 뭐예요?

vertex예요. 둘 이상이면 vertices라고 해요. 변(side)이 만나는 점이고, 아이가 corner라고 하면 "In maths, a corner is a vertex."라고 이어 주세요.

돌려 놓은 정사각형은 다이아몬드 아닌가요?

다이아몬드 모양이라고 불러도 되지만 여전히 정사각형이에요. 변 넷이 같고 직각이 넷이에요. "Turn it around. Same shape, same name!"

광고