HOW TO MEASURE DISTANCES USING TRIANGULATION

Measuring the distance across a river.

Step 1: Create a baseline and measure its length

Step 2: Measure the angles from the end of the baseline (angles 1 and 2)

Step 3:

Make a scale drawing of the triangle

Use an appropriate scale. Lets say our baseline in the above diagram is 15 m and the angles measured are 82^o for angle 1 and 67^o for angle 2.

Scale 1 cm = 5 m.

Step 4: In the scale drawing construct a perpendicular line using your compass from the baseline to the distant object.

In our scale drawing the unknown distance is _______.

Step 5: Use proportions to find the unknown distance

Make a proportion of our scale to the unknown distance in the diagram.

Therefore, the distance from the baseline to the point across the river is approximately ____________.