# find tension in 3 ropes

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A huge Halloween decoration is suspended by 3 cables. Each cable is exactly 25 m long and is attached top each of three building equidistant from each other. Each cable make an angle of 30 degrees with the side of the building to which it is attached. What is the magnitude of the tension in each cable?

So each cable makes an angle of $30^\circ$ with the vertical. They are all have the same length and therefore will have the same tension. Then the sum of three vertical components of the tension forces will balance the weight of the decoration. $$3Tcos30^\circ=mg$$  Then you can find T.