Question

a boy 1.5 told standing at the edge of the River Bank the sees is the top of a tree on the edge of the Other angle at an angle of elevation 60° standing back by 3m he sees it an angle of elevation 45 degree​

Answer 1

Answer:

This is a really simple problem involving a well-known property of right triangles. I’m not going to give you the answer, but I’m going to give you what you should learn to provide for yourself - that being to draw a picture of the problem, writing down what you know, and identifying the things you don’t know as variables. Then you apply the geometric principles you either should know, or are being taught in class, and solve the problem for the unknown quantities. The hard part is drawing an accurate picture:

Hopefully you can see that Y represents the height of the lamp post (unknown), H represents the height of the person (given as 1.5m), and 2H represents the length of the shadow cast by the person (which is twice the height of the person, or 2H). The distance between the person and the lamp post is also given as 3m (which happens to coincide with the length of the shadow, but this doesn’t affect the analysis).

You can write a very simple relationship between the two triangles, where Y is the only unknown, and solve that relationship for Y (hint: it utilizes an equivalence of two ratios).