Chair dips (straight legs)

Place your palms on a chair shoulder-width apart and extend your legs in front of you. Your elbows should be fully extended, legs extended or slightly bent at the knees (bending the knees makes the exercise easier to perform, so if you are a newbie, bent the knees at 90° angle).
Ensure your wrists, elbows and shoulders in a straight line and that your elbows are locked out.

Keeping your shoulders retracted back and pressed downwards, your chest up and your core tight, start lowering yourself down until your elbows are flexed at almost 90° and upper arms are parallel to the floor. If you can't yet lower yourself this far, then go as far as you can safely control and without feeling pain or discomfort in your shoulders.

When you reach the bottom position, push yourself back up to the starting position, driving through the palms and contracting the triceps. Push straight up and not forward.
Repeat for the recommended number of repetitions.