Mensuration

Short Answer Questions(SAQs)

How can ‘perimeter’ be defined?

A perimeter is a closed path that encompasses, surrounds or outlines either a two dimensional shape or a one-dimensional length.

What is an irregular hexagon?

An irregular hexagon is defined as a 6-sided polygon that is not regular-meaning, that all of the sides and angles do not have the same measure.

What is a polygon?

A polygon is a closed shape with least three and usually has five or more, angles and straight sides.

MCQs

1. What is the perimeter of a square of side 5 cm?

(a) 10 cm

(b) 20 cm

(c) 15 cm

(d) 25 cm

► (b) Perimeter of square = 4 × side = 4 × 5 = 20 cm.

2. Which shape has the least number of sides?

(a) Triangle

(b) Pentagon

(c) Hexagon

(d) Octagon

► (a) A triangle has the least number of sides: 3.

3. Area is measured in:

(a) cm

(b) cm²

(c) cm³

(d) m

► (b) Area is always measured in square units like cm² or m².

4. Which of these is a polygon?

(a) Circle

(b) Ellipse

(c) Hexagon

(d) Arc

► (c) A hexagon is a polygon with 6 straight sides.

5. What is the area of a rectangle with length 6 cm and breadth 4 cm?

(a) 20 cm²

(b) 24 cm²

(c) 10 cm²

(d) 12 cm²

► (b) Area = l × b = 6 × 4 = 24 cm².

6. What is the perimeter of an equilateral triangle with side 7 cm?

(a) 21 cm

(b) 14 cm

(c) 28 cm

(d) 7 cm

► (a) Perimeter = 3 × side = 3 × 7 = 21 cm.

7. Which of the following is not a polygon?

(a) Square

(b) Circle

(c) Hexagon

(d) Pentagon

► (b) A circle has no straight sides, so it is not a polygon.

8. A rectangle with sides 8 cm and 3 cm has perimeter:

(a) 22 cm

(b) 11 cm

(c) 24 cm

(d) 20 cm

► (a) P = 2(l + b) = 2(8 + 3) = 22 cm.

9. The area of a square of side 6 cm is:

(a) 36 cm²

(b) 12 cm²

(c) 18 cm²

(d) 30 cm²

► (a) Area = side × side = 6 × 6 = 36 cm².

10. A polygon with 8 sides is called:

(a) Hexagon

(b) Octagon

(c) Heptagon

(d) Nonagon

► (b) A polygon with 8 sides is called an octagon.

11. Which unit is used to measure perimeter?

(a) cm²

(b) cm

(c) cm³

(d) m²

► (b) Perimeter is a length, so measured in cm or m.

12. A triangle with all sides different is called:

(a) Isosceles

(b) Scalene

(c) Equilateral

(d) Regular

► (b) A scalene triangle has all sides of different lengths.

13. If length is 10 cm and breadth is 5 cm, area = ?

(a) 50 cm²

(b) 15 cm²

(c) 100 cm²

(d) 45 cm²

► (a) Area = l × b = 10 × 5 = 50 cm².

14. A closed shape made with only straight lines is:

(a) Polygon

(b) Arc

(c) Spiral

(d) Circle

► (a) A polygon is made of straight-line segments and is closed.

15. A square has area 49 cm². What is the side?

(a) 6 cm

(b) 7 cm

(c) 8 cm

(d) 5 cm

► (b) Side = √49 = 7 cm.

16. A regular polygon has all sides:

(a) Different

(b) Equal

(c) Curved

(d) Zero

► (b) Regular polygons have equal sides and angles.

17. What is the perimeter of an equilateral triangle of side 6 cm?

(a) 12 cm

(b) 18 cm

(c) 24 cm

(d) 20 cm

► (b) Perimeter = 3 × 6 = 18 cm.

18. Area of square with side √81 cm is:

(a) 9 cm²

(b) 81 cm²

(c) 27 cm²

(d) 18 cm²

► (b) Side = √81 = 9 ⇒ Area = 9 × 9 = 81 cm².