Group the pupils into 6 teams. Provide each group with the definition of the different kinds of lines. Then, flash the cards with drawings of the different kinds of lines one at a time and ask the pupils to post the meaning of the word on the board.

Game – “What Am I?”

1. I am the common endpoint of an angle.

2. I am an angle whose measure is 90°.

3. I am an angle whose measure is less than 90°.

4. I am an angle whose measure is more than 90° but less than 180°.

1. vertex

2. Right angle

3. Acute angle

4. Obtuse angle

Look around the classroom/garden.

• What shapes can you see?

The Math class of Mr. Raposas drew two kind of polygons. Two girls showed their drawings. Dioleta drew a 3-sided polygon, while Lolita had a 4-sided polygon.

• What is a polygon?

(A polygon is a closed figure made up of several lien segments that are joined together. The line segments are called sides and do not cross each other. There are exactly two sides that meet at a point.)

• What do you call a 3-sided polygon?
• What about a 4-sided polygon?

• Group yourselves into two.
• In the geoboard/graphing paper given, form a triangle or a quadrilateral out of the grid.
• Make your drawing big so that everybody in class can see it.
• After each group has finished, tell something about your output and post it on the board.

• Take a look at the different triangles and quadrilaterals on the board, do all have equal sides and angles
• What about the quadrilaterals?
• Triangles are classified according to their sides and their angles.
• Quadrilaterals also have their classifications.
• If you divide a quadrilateral diagonally you will form 2 triangles.

Mr. Tabilang bought a cartolina for his Math class. He needs two triangles of the same size without wasting any part of the cartolina. How will he divide it?

• What shapes are formed?

A triangle is a polygon with 3 sides and 3 angles.

A polygon is a closed figure made up of several line segments that are joined together.

The line segments are called sides and do not cross each other. There are exactly two sides that meet at a point.

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A quadrilateral is a polygon with 4sides and 4 angles.

Tell whether each figure is a triangle or a quadrilateral.

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1. 2. 3.

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4. 5. 6.

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A. Using the drawing below, tell whether the figure labeled by each letter is a triangle or a quadrilateral.

B

A

F

G

C

D

E

H

What is a triangle?

A triangle is a plane figure with 3 sides and 3 angles.

What is a quadrilateral?

A quadrilateral is a plane figure with 4 sides and 4 angles.

B. Answer the following questions. Draw a circle if your answer is yes and a diamond if it is No.

1. Do all triangles have 3 equal sides and 3 angles?
2. Do all quadrilaterals have 4 sides and 4 angles?
3. Can a quadrilateral be divided into 2 triangles?
4. Is any 3-sided polygon a triangle?
5. Is any 4-sided polygon a quadrilateral?

Do what is asked creatively.

Draw a rectangular garden. At the center, draw a triangular pool. Design your garden with any 4-sided object that will make it beautiful.

Draw a triangle if the object mentioned represents a triangle.�Draw a quadrilateral if it is not.

1. Abe is reading a book.
2. Ian is using a tripod in doing his experiment.
3. Amado is opening the door.
4. Gani is standing near the traffic sign that says “Children’s Crossing.”
5. Rafael is writing on the chalkboard.

Tell whether each figure is a triangle or a quadrilateral.

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1. 2. 3.

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4. 5.

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Do what each item asks you to do.

1. Give at least 2 objects that have the shape of a triangle.
2. Give at least 3 objects that have the shape of a quadrilateral.