## Thursday, August 12, 2010

### Question 2, 4, 5

2) Which of the given statements is correct? Justify your answer/s with examples.

A ) A square and a parallelogram are quadrilaterals.

B ) Opposite sides of a square and a parallelogram are parallel.

C ) A trapezoid has one pair of parallel sides.

D ) All the above

The answer is D. For A, quadrilaterals are 2-dimensional figures with 4 straight sides, and the interior angles add up to 360 degrees. Examples of quadrilaterals are squares, parallelograms, and kites. Since a square and a parallelogram are 2-dimensional figures with 4 straight sides, and the interior angles add up to 360 degrees, they are quadrilaterals. For B, squares have 2 pairs of parallel lines, while a parallelogram has a pair of parellel line at each side. Hence, opposite sides of a square and a parallelogram are parallel. For C, a trapezoid has only a pair of parellel lines. If there were more than a pair of parallel lines, it would be a parallelogram. So, all of the statements are correct.

4) All parallelograms are squares?' Do you agree with this statement?