Question

sit high enough so that your elbow are not make 90 degree angle as you type

Answer 1

Hey,
what question u need to ask just type that...
hope u will understand

Answer 2

The office workstation should let the worker sit and carry out their duties in comfort while allowing for voluntary changes in the working position.

There are three contact areas in the work space that affect the worker's posture: the seat, the work surface (commonly it is a desk top or keyboard) and the floor. To ensure the most comfortable posture possible, two of these factors have to be adjustable.

If you can afford to do nothing else, a fully adjustable chair is a "must". The other, and perhaps the most preferable option, would be a fully adjustable desk. However the price of such a desk may not make this option practical. Another effective (and cheaper) option is to use an adjustable chair and footrest to secure postural comfort.