A clinometer is an instrument which lets you estimate the height of an object (building, tree, flag-pole) by using the properties of a right angled triangle.

CLINOMETER

There are many types of clinometer:

From the simple home-made

To the more elaborate

To the unusual looking

Or even this

However each is used in the same way to measure an angle that will lead to calculating the height of an object.

To calcuate the height of a tree

Using a suitable instrument measure and record height A and distance B

Use a clinometer to measure the angle at C

Stand a suitable distance from the tree

c

The procedure is the same for any object

Measure horizontal distance to base of object

Measure vertical height of observer (to eye level)

Measure angle

x

B

A

c

Draw a Suitable diagram

Height of object is +A

xTanC

Bx B TanC

x

opp

adj

Use this as a scale diagram to find the height of the object

Or use trigonometry

A

Height of observer (M)

(A)

Horizontal distance to object (M)

(B)

Angle

(C) TanC (BXTanC)

Height of object

+ A

1.55 24 230 0.4245 10.19 11.74

x

x