Class 6 - Mathematics
Chapter - Practical Geometry : Exercise 10.2

Top Block 1
Question : 1.Construct ΔXYZ in which XY = 4.5 cm, YZ = 5 cm and ZX = 6 cm.
Answer :
To construct: ΔXYZ, where XY = 4.5 cm, YZ = 5 cm and ZX = 6 cm.

Steps of construction:
(a) Draw a line segment YZ = 5 cm.
(b) Taking Z as centre and radius 6 cm, draw an arc.
(c) Similarly, taking Y as centre and radius 4.5 cm, draw another arc which intersects first arc at point X.
(d) Join XY and XZ.
It is the required ΔXYZ.
(a) Draw a line segment YZ = 5 cm.
(b) Taking Z as centre and radius 6 cm, draw an arc.
(c) Similarly, taking Y as centre and radius 4.5 cm, draw another arc which intersects first arc at point X.
(d) Join XY and XZ.
It is the required ΔXYZ.
Question : 2.Construct an equilateral triangle of side 5.5 cm.
Answer :
To construct: A ΔABC where AB = BC = CA = 5.5 cm

Mddle block 1
Steps of construction:
(a) Draw a line segment BC = 5.5 cm
(b) Taking points B and C as centre and radius 5.5 cm, draw arcs which intersect at point A.
(c) Join AB and AC.
It is the required ΔABC.
(a) Draw a line segment BC = 5.5 cm
(b) Taking points B and C as centre and radius 5.5 cm, draw arcs which intersect at point A.
(c) Join AB and AC.
It is the required ΔABC.
Question : 3.Draw ΔPQR with PQ = 4 cm, QR = 3.5 cm and PR = 4 cm. What type of triangle is this?
Answer :
To construction: ΔPQR, in which PQ = 4 cm, QR = 3.5 cm and PR = 4 cm.

Steps of construction:
(a) Draw a line segment QR = 3.5 cm.
(b) Taking Q as centre and radius 4 cm, draw an arc.
(c) Similarly, taking R as centre and radius 4 cm, draw an another arc which intersects first arc at P.
(d) Join PQ and PR.
It is the required isosceles ΔPQR.
(a) Draw a line segment QR = 3.5 cm.
(b) Taking Q as centre and radius 4 cm, draw an arc.
(c) Similarly, taking R as centre and radius 4 cm, draw an another arc which intersects first arc at P.
(d) Join PQ and PR.
It is the required isosceles ΔPQR.
Question : 4.Construct ΔABC such that AB = 2.5 cm, BC = 6 cm and AC = 6.5 cm. Measure ∠B.
Answer :
To construct:ΔABC in which AB = 2.5 cm, BC = 6 cm and AC = 6.5 cm.

Steps of construction:
(a) Draw a line segment BC = 6 cm.
(b) Taking B as centre and radius 2.5 cm, draw an arc.
(c) Similarly, taking C as centre and radius 6.5 cm, draw another arc which intersects first arc at point A.
(d) Join AB and AC.
(e) Measure angle B with the help of protractor.
It is the required ΔABC where ∠B = 80o.
(a) Draw a line segment BC = 6 cm.
(b) Taking B as centre and radius 2.5 cm, draw an arc.
(c) Similarly, taking C as centre and radius 6.5 cm, draw another arc which intersects first arc at point A.
(d) Join AB and AC.
(e) Measure angle B with the help of protractor.
It is the required ΔABC where ∠B = 80o.