Question

a framed picture of weight 15N is hung on a wall, using a piece of string. The ends of the string are tied to two points, 0.60 m apart on the same horizontal level, on the back of the picture.Find the tension in the string if the string is 1.0m long

Answer 1

make two right triangles.
Consider one side.

Theta=arccos .3/.5

but sinTheta=1/2 weight/tension

tension=.5*15/sinTheta