Page 91 - Mathematics Class - X

PROJECT 4

AIM
Application of geometry in day-to-day life.

MATERIALS REQUIRED

A thick chart paper A small weight (a metal washer)
A soft-drink straw A geometry box
A flexible string

PROCEDURE
Step 1: On the top side of the chart paper construct a large protractor as shown in figure.
Step 2: Fix the soft-drink straw at the centre point O (as shown in figure) using a nail. Ensure that the straw lies
at your eye level.
Step 3: From the nail, suspend a weight using a flexible string as shown in figure.

Straw

Step 4: A clinometer (also called inclinometer, as it is used for measuring the angle of slope, elevation or
inclination of an object) is thus prepared.
Step 5: Measure the distance d of the object (lamp post) from the clinometer.
Step 6: Look through the straw and keep on tilting it till you are able to see the top of the lamp post.

Step 7: Hold the clinometer in this position and record the angle of elevation of the top of the lamp post.
Step 8: Record your height also.

OBSERVATIONS AND CALCULATIONS
Distance of the object from you = d

Angle of elevation of the top of the lamp post with respect to your eye = q
Your height = h
1
Therefore, height of the lamp post h = h + d tan q.
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