A folding catwalk of uniform density and length 3r is attached to a wall by a hinge. At the other end it is supported by a cable which makes an angle of above the horizontal. If a person of mass m stands a distance r from the wall what is the tension, T, in the support cable? The gravitational field is a constant g and the mass of the catwalk itself is 2m.

[To enter the angle in the formula use the name 'theta' (without quotes).]