Ncert Solutions For Class 7 Maths Ex 10.2

Ncert Solutions For Class 7 Maths Chapter 10 Ex 10.2

 

Q1 :

Construct Δ PQR in which PQ = 4.5 cm , QR = 5 cm and RP = 6cm.

Solution:

Construct: Δ PQR, where PQ = 4.5 cm, QR = 5 cm, RP = 6 cm

Construction:

(i) Draw a line segment QR = 5 cm.

(ii) Taking R as center and radius 6cm, draw arc.

(iii) Similarly, taking Q as center and radius 4.5 cm  draw another arc which intersects the first arc at point P

(iv) Join PR and PR

It is the required Δ PQR

 2.1

 

Q2:

Construct an equilateral triangle of side 5.5 cm

Solution:

To construct: A Δ PQR where PQ = QR = QP = 5.5 cm

Construction :

(i) Draw a line segment BC = 5.5 cm

(ii) Taking points Q and R as centers and radius 5.5 cm , draw arcs which intersect at point P.

(iii) Join PQ and PR

It is the required Δ PQR

 2.2

 

Q3:

Draw Δ ABC with AB = 4cm, BC = 3.5 and AC = 4cm. What type of triangle is this?

Solution:

To construct: Δ ABC, in which AB = 4cm, BC = 3.5 and AC = 4 cm

Construction:

(i) draw a line segment BC = 3.5 cm

(ii) Taking B as center and radius 4 cm, draw an arc.

(iii) Similarly, taking C as center and radius 4 cm, draw another arc which intersects first arc at A.

(iv) Join AB and AC.

It is the required isosceles Δ ABC

2.3

 

 Q4:

Construct Δ PQR such that PQ = 2.5 cm , QR = 6 cm and PR = 6.5 cm. Measure Q

Solution:

To Construct:

Δ PQR such that PQ = 2.5 cm, QR = 6cm and PR = 6 cm and PR = 6.5 cm

Construction :

(i) Draw a line segment QR = 6cm

(ii) Taking B as center and radius 2.5 cm, draw an arc.

(iii) Similarly, taking C as center and radius 6.5 cm , draw another arc which intersects first arc at point P

(iv) Join PQ and PR

(v) Measure angle Q with the help of protractor

It is the required Δ PQR where Q = 80o

2.4