10.1 Angle of Elevation and Angle of Depression (Part 1)
1. Angle of elevation is the acute angle measured from a horizontal line up to the line of sight.
![](http://spmmathematics.blog.onlinetuition.com.my/wp-content/uploads/sites/5/2015/03/Picture5.png)
![](http://spmmathematics.blog.onlinetuition.com.my/wp-content/uploads/sites/5/2015/03/Picture5.png)
Example 1:
![](http://spmmathematics.blog.onlinetuition.com.my/wp-content/uploads/sites/5/2015/03/Picture7.png)
![](http://spmmathematics.blog.onlinetuition.com.my/wp-content/uploads/sites/5/2015/03/Picture7.png)
Angle of elevation of object O from P = ∠OPA
2. Angle of depression is the acute angle measured down from a horizontal line to the line of sight.
![](http://spmmathematics.blog.onlinetuition.com.my/wp-content/uploads/sites/5/2015/03/Picture6.png)
![](http://spmmathematics.blog.onlinetuition.com.my/wp-content/uploads/sites/5/2015/03/Picture6.png)
Example 2:
![](http://spmmathematics.blog.onlinetuition.com.my/wp-content/uploads/sites/5/2015/03/Picture8.png)
![](http://spmmathematics.blog.onlinetuition.com.my/wp-content/uploads/sites/5/2015/03/Picture8.png)
Angle of depression of object O from P = ∠OPA