Question

Two familiar triangles are given below.
30°
459
12
2.
1
13
450
60°
1
The sides of right triangles are calculated Using this, calculate the perimeter of the
triangles given below.
ZBAD
ZCAD
A
AB
cm
BD
II
cm
300
30
CD
cm
В.
D
BC
cm
AC
cm
Find the perimeter of triangle ABC
R
ZPRS
=
II
ZQRS
2
cm
cm
459
30°
RS
PS
QS
PR
PQ
cm
S
cm
cm
Find the perimeter of triangle PQR​

Answer 1

Answer:

Let △ABC and △DEF be two similar triangles of perimeters P

1

and P

2

respectively.

Also, let AB=12 cm, P

1

=30 cm and P

2

=20 cm.

Then,

DE

AB

=

EF

BC

=

DF

AC

=

P

2

P

1

[∵ Ration of corresponding sides of similar triangles is equal to the ratio of their perimeters]

⇒

DE

AB

=

P

2

P

1

⇒

DE

12

=

20

30

⇒ DE=

30

12×20

cm=8cm

Hence, the corresponding side of the second triangle is 8 cm