2.(d) Give reasons for the following :
(d) Squares, rectangles, parallelograms are all quadrilaterals.
2.(b) Give reasons for the following :
(b) A rectangle can be thought of as a special parallelogram.
1. Say True or False :
(a) Each angle of a rectangle is a right angle.
(b) The opposite sides of a rectangle are equal in length.
(c) The diagonals of a square are perpendicular to one another.
(d) All the sides of a rhombus are of equal length.
(e) All the sides of a parallelogram are of equal length.
(f) The opposite sides of a trapezium are parallel.
3. Name each of the following triangles in two different ways: (you may judge the nature of the angle by observation)
2. Match the following :
|Measure of triangles||Types of triangle|
|(i) 3 sides of equal length||(a) Scalene|
|(ii) 2 sides of equal length||(b) Isoscles right angled|
|(iii) All sides of different length||(c) Obtuse angled|
|(iv) 3 acute angles||(d) Right angled|
|(v) 1 right angle||(e) Equilateral|
|(vi) 1 obtuse angle||(f) Acute angled|
|(vii) 1 right angle with two sides of equal length||(g) Isosceles|
1. Name the types of following triangles :
(a) Triangle with lengths of sides 7 cm, 8 cm and 9 cm.
(b) with AB = 8.7 cm, AC = 7 cm and BC = 6 cm.
(c) such that PQ = QR = PR = 5 cm.
(e) with and XY = YZ.
(f) with , and
4. Study the diagram. The line is perpendicular to line
(a) Is CE = EG?
(b) Does PE bisect CG?
(c) Identify any two line segments for which PE is the perpendicular bisector.
(d) Are these true?
(i) AC > FG
(ii) CD = GH
(iii) BC < EH.
3. There are two set-squares in your box. What are the measures of the angles that are formed at their corners? Do they have any angle measure that is common?
2. Let be the perpendicular to the line segment . Let and intersect in the point A. What is the measure of ?
1. Which of the following are models for perpendicular lines :
(a) The adjacent edges of a table top.
(b) The lines of a railway track.
(c) The line segments forming the letter ‘L’.
(d) The letter V.
11. Measure and classify each angle :
8. Find the measure of the angle shown in each figure. (First estimate with your eyes and then find the actual measure with a protractor).
7. Fill in the blanks with acute, obtuse, right or straight :
(a) An angle whose measure is less than that of a right angle is______.
(b) An angle whose measure is greater than that of a right angle is ______.
(c) An angle whose measure is the sum of the measures of two right angles is _____.
(d) When the sum of the measures of two angles is that of a right angle, then each one of them is ______.
(e) When the sum of the measures of two angles is that of a straight angle and if one of them is acute then the other should be _______.
5. Which angle has a large measure? First estimate and then measure.
Measure of Angle A =
Measure of Angle B =