Page 162 - Start Up Mathematics_5

EXERCISE 12.2

1. For each of these objects, name the pairs of all parallel and perpendicular lines.

A B A
A B

(a) D C (b) (c) D B

E F C
E D C

H G

2. Look at the given figure and choose the correct options to answer the questions. Give
reasons to justify your answer.

(a) __________ is parallel to KL.
(i) GH (ii) IJ (iii) EF

(b) EF and AB intersect at __________. E I K
(i) O (ii) G (iii) H A O G B

(c) __________ is perpendicular to EF. H
C D
(i) GH (ii) AB (iii) KL F J L
(d) __________ and __________; __________ and
__________ are two pairs of parallel lines.

(i) AB, CD (ii) EF, KL (iii) KL, IJ
(e) __________ and __________ are perpendicular to KL.

(i) IJ, CD (ii) AB, CD (iii) AB, IJ

Triangle

A three-sided closed figure formed by three line segments is called a triangle. The symbol
for a triangle is D.

Parts of a triangle

A triangle has 3 sides, 3 angles and 3 vertices. Look angle P vertex
at D PQR. ∠P side
• PQ, QR and PR are its 3 sides. side

• ∠QPR, ∠PQR and ∠PRQ or ∠P, ∠Q and ∠R are its vertex
3 angles. vertex ∠Q ∠R

• P, Q and R are its 3 vertices. Q angle side angle R

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