Chuck stands with his feet close to the load, shoulder-width apart, one foot slightly in front of the other for balance. He squats down, bending at the knees and keeping his back as vertical as possible. Once he's close enough, Chuck makes sure he has a firm grasp of the object before beginning the lift, slowly straightening his legs and lifting slowly. He stands up straight and keeps his load close to his body. Is Chuck using a safe lifting technique?

yes

Explanation:the proper lifting technique is Your feet should be shoulder-width apart, with one foot slightly ahead of the other. If needed, put one knee to the floor and your other knee in front of you, bent at a right angle,  Slowly lift by straightening your hips and knees (not your back). Bend your hips and knees to squat down to your load, keep it close to your body

a, b, c - sides of a triangle

a + b > c

a + c > b

b + c > a

we have a = 5m and b = 11m. substitute:

5 + 11 > c

16 > c → c < 16

5 + c > 11         subtract 5 from both sides

c > 6

11 + c > 5         subtract 11 from both sides

c > -6

c < 16 and c > 6 and c > -6

thereofre your answer is 6m < c < 16m