Calculate the length of the shadow in the lake:) help please

Question

Hi guys this is an easy question but i'm just confused Could U help me please?

this is the question :

There is a boat on a lake ( with the depth of 20 m ) and the boat has a lamp on the height of 6 meters from the surface of water. ( the lamp is in the middle of the boat ) calculate the length of the shadow of the boat in the water .( the boat is 16 meters long)

i just translated the problem from my mother tongue to English so it may be a little unclear . Sorry because of that!

Answer 1

according to the given data length of the boat is :16 m(B)

depth of the water is :20 m(W)

the boat has a lamp on the middle of the boat and its heigth is: 6 m(H)

so length of the  shadow of the boat in the water is(L):16+10=26 m