Chapter 5: Understanding Elementary Shapes

(a) The adjacent edges of a table top are perpendicular to each other.

(b) The lines of a railway track are parallel to each other.

(c) The line segments forming the letter ‘L’ are perpendicular to each other

(d) The sides of letter V are inclined forming an acute angle.

Therefore (a) and (c) are models for perpendicular lines.

From the figure it is clear that the measure of ∠PAY is 90⁰

The measure of angles in one set square are 30⁰, 60⁰ and 90⁰

The other set square has a measure of angles 45⁰, 45⁰ and 90⁰

Yes, the angle of measure 90⁰ is common in between them

(a) Yes, since, CE = 2 units and EG = 2 units respectively

(b) Yes. Since, CE = EG as both are of 2 units. Hence PE bisect CG

(c) and are the line segments for which PE is the perpendicular bisector

(d) (i) True. Since AC = 2 units and FG = 1 unit

∴ AC > FG

(ii) True because both are of 1 unit

(iii) True. Since, BC = 1 unit and EH = 3 units

∴ BC < EH