Question

A lotus is 20cm above the water surface in a pond and its stem is partly
below the water surface. As the wind blew, the stem is pushed aside so
that the lotus touched the water at 40cm away from the original position of
the stem. Originally how much of the stem was below the water surface?


PLZ SOLVE THIS FIRELEO​

Answer 1

Answer:

As shown in the figure,

A lotus is 20cm20cm above the water surface in a pond

AD=20 cm,

Height of stem below the water surface =BD=x=?

The lotus touched the water 40 cm away from the original position of the stem,

CD=40 cm

Now, in △ BCD,

BC

2

=BD

2

+CD

2

(20+x)

2

=x

2

+40

2

(400+x

2

+40x)=x

2

+1600

40x=1200

x=30 cm

Hence, the stem was below the water surface originally by 30 cm.