Question

question:9 a 5m 60cm high vertical pole cast a shadow 3m20cm long.find at the same time (i) the length of the shadow cast by another pole 10m50cm high (ii) the height of a pole which casts a shadow 5m long.

Answer 1

Answer:

Given that, Height(H)=5.6 m and Length (Shadow)=3.2 m

See the attached file for diagram-

Here calculate the value of alpha by applying tan(alpha)=H/B

tan(alpha)=5.6/3.2=1.75;

alpha=Inverse of tan(1.75)=60 degree (appx value 60.2)

Solution of (i)

Now alpha is 60 and Height of the pole is 10.5

So  tan60=10.5/B1, by solving this

we get

B1(Length of shadow)=6m

Solution of (ii)

Here alpha is same=60 and shadow length is 5m

so tan60=H2/5;

H2(Length of the pole)=8.75 m