### Su En - E-Learning Activity 3

Question 1

Justify the statement: ‘A square is a rhombus but a rhombus is not a square’.

- Yes, the statement is correct. The square has 4 sides but it is perpendicular to each other and the side are all equal. Whereby the Rhombus has 4 sides, but it need not be perpendicular to each other. It can be slanted but still called a rhombus.

Question 2

- Answer: D

a) the square and the parallelogram must both be four sided
b) the square and the parallelogram's each side must be parallel to the one opposite it.
c) a trapezoid must have one parallel side.

Question 4

Justify the statement: 'All parallelograms are squares?'

- I do not agree with this statement. All parallelograms need not be squares, but squares are one kind of parallelogram. Parallelograms' sides must be parallel to the one opposite it. But it need not be perpendicular like the square. It can be slanted as well.

#### 2 comments:

1. Well done Su En:
Can we call a rhombus square ? Or can we call square, rhombus? Look at properties of both and comment. Good to check out the term 'subset'.

2. Properties of a:
rhombus:
- all sides must have equal length
- all sides must be parallel to the side opposite it
square:
- all sides must have equal length
- all sides must be parallel to the side opposite it
- there must be 4 right angles at each point that the lines come in contact

We can call a square a rhombus, but a rhombus needn't be a square.

definition of subset:
noun
a part of a larger group of related things.
• Mathematics a set of which all the elements are contained in another set.

So, based on my understanding, the square is a subset of the rhombus.
Is that correct?