Question

6. In Fig. 12.99, DE || BC; AD= 3 cm, DB = 2 cm, area
of A ABC = 10 cm'. Find the area of A ADE. (SC)
R
B В
Fig. 12.99
Fig. 12.100​

Answer 1

Answer:

Given : DE∥BC in △ ABC,

Using Basic proportionality theorem,

∴

DB

AD

=

EC

AE

⇒

3

1.5

=

EC

1

⇒EC=

1.5

3

EC=3×

15

10

=2 cm

EC=2 cm.

(ii) In △ABC,DE∥BC (Given)

Using Basic proportionality theorem,

∴

DB

AD

=

EC

AE

⇒

7.2

AD

=

5.4

1.8

⇒AD=1.8×

5.4

7.2

=

10

18

×

10

72

×

54

10

=

10

24

⇒AD=2.4cm

So, AD=2.4 cm