The figure ABCD below is a scale drawing representing a rectangular garden of length 60 m and width 30m.
![](https://www.easyelimu.com/images/kcsepastpapers/maths/kcse21mathpp2q9.PNG)
The owner intends to plant trees in the garden. Each tree, T, must be at least 21 m from the edge AB. In addition, angle ATB must be acute.
Show by shading the exact region where the trees can be planted.