# Free Understanding Elementary Shapes 02 Practice Test - 6th grade

### Question 1

State whether the following statement is true or false.

180∘ is an example of an obtuse angle.

True

False

#### SOLUTION

Solution :B

An obtuse angle is greater than 90∘and less than 180∘. If the angle is 180∘, then it is called a straight angle.

### Question 2

Take two regular tetrahedrons and stick them along a common base. The number of edges in the new three-dimensional shape formed is? (Enter number in digits)

#### SOLUTION

Solution :A tetrahedron has 6 edges. Two tetrahedrons will have 12 edges. After sticking them, 3 edges will be common. So, number of edges = 12 - 3 = 9

### Question 3

How many right angles do you need to add to get a straight angle?

#### SOLUTION

Solution :Two right angles = 90∘ + 90∘ = 180∘ = Straight angle.

### Question 4

Match the following

1- c; 2- a; 3- b

1- c; 2- b; 3- a

1- a; 2- c; 3- b

1- a; 2- b; 3- c

#### SOLUTION

Solution :A

1 - c (as the sides are not equal)

2 - a (as two sides are equal)

3 - b (as all sides are equal)

### Question 5

Which one of the polygons mentioned below are regular polygons?

Rhombus

Square

Rectangle

Isosceles triangle

#### SOLUTION

Solution :B

In a regular polygon, all the angles should be same and all the sides should be equal in length.In the given options, only square has all its sides equal and all its angles equal.

### Question 6

If exactly two sides of a triangle are equal, then it is called a/an _______.

#### SOLUTION

Solution :B

If exactly two sides of a triangle are equal, then the triangle is called an isosceles triangle.

### Question 7

Find which of the following are true:

1.All rhombuses are squares

2.All squares are rectangles

3.All rectangles are parallelograms

4.All parallelograms are quadrilaterals

5.All parallelograms are rhombuses

1, 2 and 3

2, 3 and 4

3, 4 and 5

only 1

#### SOLUTION

Solution :B

Let us analyze them:

- Squares have all angles =90∘, which is not true for rhombuses.
- Rectangles have opposite sides equal and all angles =90∘, true for squares.
- Rectangles have opposite sides equal and parallel, true for parallelograms.
- Parallelograms have 4 sides, true for quadrilaterals.
- Parallelograms may have unequal sides, not true for rhombuses.
So, only 2, 3 and 4 are true.

### Question 8

If we consider the angle made between the hour hand and the minute hand, which of the following times make an acute angle?

04:30

05:00

06:00

09:00

#### SOLUTION

Solution :A

At 04:30, the angle between the hour hand and minute hand is less than 90

^{o }and at the other given times, the angle between the minute and the hour hand is more than 90^{o}.

### Question 9

Which of the following are the perfect models of two perpendicular lines?

Corners of a triangular shaped table( its not a right angled triangle)

Railway tracks

Adjacent walls of a rectangular room.

The line segments that make the 'T' shape

#### SOLUTION

Solution :C and D

Corners of a triangular table which is not a right angled triangle are not perpendicular to each other.

Railway tracks are parallel.

The adjacent walls of a rectangular room are perpendicular to each other, so are the line segments that make 'T'.

### Question 10

A line segment is defined as

a curved segment of line

a line with finite length

a line having one end-point

same as line

#### SOLUTION

Solution :B

A line having a fixed/finite length is known as line segment. It can also be defined as a line having two end points. On the other hand, a line having one end point is known as Ray.