Shapes: Mathematics Darjah 3 questions

Section A: objective questions

8 marks

Choose the best answer for each question.

What is the name of the prism below?

Square prism
Triangular prism
Rectangular prism
Pyramid

Show answerHide answer

Its two opposite bases are triangles, so it is a triangular prism. A prism is named after the shape of its base.

For the teacher: Remembering, low difficulty, standard 7.1.1

Textbook p. 86

A tissue box is a cuboid. How many vertices does it have?

Show answerHide answer

A cuboid has 8 vertices (4 at the front and 4 at the back). 6 is the number of flat surfaces and 12 is the number of edges.

For the teacher: Remembering, low difficulty, standard 7.1.2

Textbook p. 86

Which shape is not a prism?

Show answerHide answer

D is a cylinder. It has a curved surface, so it is a non-prism. A, B and C are a cube, a cuboid and a triangular prism.

For the teacher: Understanding, low difficulty, standard 7.2.1

Textbook p. 87

Name the polygon that has these characteristics:
8 straight sides
8 corners

Hexagon
Heptagon
Pentagon
Octagon

Show answerHide answer

An octagon has 8 straight sides and 8 corners. A hexagon has 6, a heptagon 7 and a pentagon 5.

For the teacher: Remembering, low difficulty, standard 7.3.1

Textbook p. 90

What is a characteristic of the polygon below?

A regular polygon with six sides — Diagram 2

6 straight sides
8 straight sides
Has curved sides
5 corners

Show answerHide answer

The polygon is a hexagon. It has 6 straight sides and 6 corners, and no curved sides.

For the teacher: Understanding, low difficulty, standard 7.3.1

Textbook p. 89

Which shape is a regular polygon?

Show answerHide answer

C is a regular heptagon: 7 straight sides of equal length. A and B have sides of different lengths, and D (a circle) has a curved side.

For the teacher: Understanding, medium difficulty, standard 7.3.1

Textbook p. 89

The road sign "Berhenti" has the shape of a regular octagon. How many axes of symmetry does it have?

Show answerHide answer

A regular polygon has as many axes of symmetry as sides. An octagon has 8 sides, so it has 8 axes.

For the teacher: Applying, medium difficulty, standard 7.4.1

Textbook p. 92

In which diagram is the blue dashed line an axis of symmetry?

Show answerHide answer

Fold the triangle along the line down its middle and the two halves overlap exactly. The other lines make two parts that do not fit on top of each other when folded.

For the teacher: Analysing, high difficulty, standard 7.4.1

Textbook p. 92

Section B: structured questions

24 marks

Answer all questions. Show your working.

Diagram 4 shows a cuboid. X, Y and Z are parts of the cuboid.

Cuboid with a vertex X, a flat surface Y and an edge Z — Diagram 4

[1 mark] (a)X is a

vertexedgeflat surface

Show answerHide answer

vertex

[1 mark] (b)Y is a

vertexedgeflat surface

Show answerHide answer

flat surface

[1 mark] (c)Z is a

vertexedgeflat surface

Show answerHide answer

edge

For the teacher: Remembering, low difficulty, standard 7.1.2

Textbook p. 86

Diagram 5 shows a triangular prism. Count its parts. (The dashed lines show the edges at the back.)

Triangular prism with hidden edges dashed — Diagram 5

[1 mark] (a)Number of flat surfaces = ______

Show answerHide answer

5 (2 triangles + 3 rectangles = 5) [1]1

Tick each point you got.

[1 mark] (b)Number of vertices = ______

Show answerHide answer

6 (3 at the front + 3 at the back = 6) [1]1

Tick each point you got.

[1 mark] (c)Number of edges = ______

Show answerHide answer

9 (3 + 3 + 3 = 9) [1]1

Tick each point you got.

For the teacher: Applying, low difficulty, standard 7.1.2

Textbook p. 86

Diagram 6 shows a regular polygon with three lines P, Q and R.

Regular pentagon with three dashed lines P, Q and R — Diagram 6

[1 mark] (a)What is the name of the polygon?

Show answerHide answer

Pentagon [1]1

Tick each point you got.

[1 mark] (b)Give one characteristic of the polygon.

Show answerHide answer

5 straight sides / 5 corners / sides of equal length / no curved sides [1]1

Tick each point you got.

[1 mark] (c)Which line is an axis of symmetry?

PQR

Show answerHide answer

Fold along P and the two halves overlap exactly. Q and R cut the pentagon into two parts that do not match.

For the teacher: Understanding, medium difficulty, standard 7.4.1

Textbook p. 92

Puan Salina shows three pictures to her class. Amin must choose the picture of a prism.

[1 mark] (a)Which picture does Amin choose?

CylinderConeCube

Show answerHide answer

Cube

[2 marks] (b)Give two reasons for your answer.

Show answerHide answer

Any 2 points

It has 5 or more flat surfaces (6 flat surfaces) [1]1
It has 2 opposite surfaces (bases) of the same shape and size [1]1
It has no curved surfaces [1]1

The cylinder and the cone have curved surfaces, so they are non-prisms.

Tick each point you got.

For the teacher: Analysing, medium difficulty, standard 7.5.1

Textbook p. 94

Solve the problems.

[1 mark] (a)Wong cuts a shape. It has 3 corners more than a pentagon. What is the shape?

Show answerHide answer

5 + 3 = 8 corners, so it is an octagon [1]1

Tick each point you got.

[1 mark] (b)Mei Ling draws a polygon. It has 1 side fewer than an octagon. What is the polygon?

Show answerHide answer

8 − 1 = 7 sides, so it is a heptagon [1]1

Tick each point you got.

For the teacher: Applying, medium difficulty, standard 7.5.1

Textbook p. 94

Siti makes a pattern for her Hari Raya card using paper shapes, as in Diagram 7.

Pattern made of seven six-sided shapes — Diagram 7

[1 mark] (a)What is the name of the shape used in the pattern?

Show answerHide answer

Hexagon [1]1

Tick each point you got.

[1 mark] (b)How many of these shapes did Siti use?

Show answerHide answer

7 [1]1

Tick each point you got.

For the teacher: Understanding, low difficulty, standard 7.3.2

Textbook p. 91

Chin has four picture cards K, L, M and N.

[1 mark] (a)Which card has 4 axes of symmetry?

KLMN

Show answerHide answer

A square has 4 axes: across, down and along both diagonals.

[1 mark] (b)How many axes of symmetry does card N have?

Show answerHide answer

2 (one across the middle and one down the middle) [1]1

The diagonals of a rectangle are not axes of symmetry.

Tick each point you got.

For the teacher: Analysing, high difficulty, standard 7.5.1

Textbook p. 95

Aiman says, "A tin of milk is a prism because its top and bottom are the same shape."

[1 mark] (a)Is Aiman correct?

YesNo

Show answerHide answer

[1 mark] (b)Explain your answer.

Show answerHide answer

A tin of milk is a cylinder; it has a curved surface (and only 2 flat surfaces), so it is a non-prism [1]1

Tick each point you got.

For the teacher: Evaluating, high difficulty, standard 7.2.1

Textbook p. 87

Diagram 9 shows three nets, P, Q and R.

Net Q: three rectangles and two triangles

[1 mark] (a)Which net can be folded into a prism?

PQR

Show answerHide answer

Q folds into a triangular prism. P makes a pyramid and R makes a cylinder (both non-prisms).

[1 mark] (b)Name the shape formed by net P.

Show answerHide answer

Pyramid [1]1

Tick each point you got.

For the teacher: Analysing, medium difficulty, standard 7.2.1

Textbook p. 88

Create a riddle ("Who am I?") about a hexagon for your friend to guess.

[2 marks] (a)Write two clues about the hexagon.

Show answerHide answer

Example: I am a flat shape. I have 6 straight sides and 6 corners. Bees make their honeycomb with me. Who am I?

Any 2 points

A correct clue about its sides: 6 straight sides (of equal length) [1]1
A correct clue about its corners: 6 corners [1]1
Another correct clue, e.g. a 2-D shape with no curved sides, 6 axes of symmetry, or found in a honeycomb [1]1

Tick each point you got.

For the teacher: Creating, high difficulty, standard 7.3.1

Textbook p. 90

Section A: objective questions

Question 1

Question 2

Question 3

Question 4

Question 5

Question 6

Question 7

Question 8

Section B: structured questions

Question 9

Question 10

Question 11

Question 12

Question 13

Question 14

Question 15

Question 16

Question 17

Question 18