Question

1. In Fig. 9.15, ABCD is a parallelogram, AE 1 DC
and CF perpendicular AD. If AB = 16 cm, AE = 8 cm and
CF= 10 cm, find AD.​

Answer 1

Answer:

ar(llgm ABCD)= b×h

=AD×C.F.

=AD×10 cm........(1)

ar (llgm ABCD)=b×h

=CD×AE

=16×8cm(AB=CD=16cm)

=128cm........(2)

From 1 and 2 we get

AD×10=128cm

AD=12.8cm

Answer 2

Question :-

In figure, ABCD is a parallelogram, AE ⊥ DC and CF ⊥ AD. If AB = 16 cm, AE = 8 cm and CF = 10 cm, find AD.

Answer :-

We have, AE ⊥ DC and AB = 16 cm

∵ AB = CD [Opposite sides of parallelogram]

∴ CD = 16 cm

Now, area of parallelogram ABCD = CD x AE

= (16 x 8) cm2 = 128 cm2 [∵ AE = 8 cm]

Since, CF ⊥ AD

∴ Area of parallelogram ABCD = AD x CF

⇒ AD x CF = 128 cm

⇒ AD x 10 cm = 128 cm2 [∵ CF= 10 cm]

⇒ AD = 128/10 cm = 12.8 cm 10

Thus, the required length of AD is 12.8 cm

Hope it helps ❤ Mrk as brainliest