An easy exercise for your triceps is the kickback.
Hold a dumbbell in the right hand. Stand in a split-stance position with the left leg forward. Keep your weight distributed through the heels of both feet. Brace your abdominal and core muscles to stabilize the spine. Slowly lean forward, shifting most of your upper extremity body weight into the left side. Pull your shoulder blades down and back. Your head should be aligned with your spine. Maintain these engagements throughout the exercise.
Bend your right elbow bringing your upper arm parallel to, and close to, your torso. Your forearm should hang perpendicular to the floor.
Exhale and slowly straighten your elbow. Your upper arm should remain stationary next to your torso. Do not allow the upper arm to rise during the movement. Do not allow the low back to sag or your torso to rotate.
Inhale and slowly bend your elbow, returning to starting position.
Repeat and change sides.