| Date | November 2009 | Marks available | 2 | Reference code | 09N.1.sl.TZ0.7 |
| Level | SL only | Paper | 1 | Time zone | TZ0 |
| Command term | Justify | Question number | 7 | Adapted from | N/A |
Question
Consider the statement p:
“If a quadrilateral is a square then the four sides of the quadrilateral are equal”.
Write down the inverse of statement p in words.
Write down the converse of statement p in words.
Determine whether the converse of statement p is always true. Give an example to justify your answer.
Markscheme
If a quadrilateral is not a square (then) the four sides of the quadrilateral are not equal. (A1)(A1) (C2)
Note: Award (A1) for “if…(then)”, (A1) for the correct phrases in the correct order.
[2 marks]
If the four sides of the quadrilateral are equal (then) the quadrilateral is a square. (A1)(A1)(ft) (C2)
Note: Award (A1) for “if…(then)”, (A1)(ft) for the correct phrases in the correct order.
Note: Follow through in (b) if the inverse and converse in (a) and (b) are correct and reversed.
[2 marks]
The converse is not always true, for example a rhombus (diamond) is a quadrilateral with four equal sides, but it is not a square. (A1)(R1) (C2)
Note: Do not award (A1)(R0).
[2 marks]
Examiners report
There was confusion among some students about which was the inverse and converse of the given statement.
There was confusion among some students about which was the inverse and converse of the given statement.
There was confusion among some students about which was the inverse and converse of the given statement. Part (c) was poorly done with very few students able to provide an example that shows that the converse is not always true.
