11 A vertical mast, XY, is positioned on horizontal ground. The mast is supported by four cables attached to the mast at P and to the ground at points A, B, C and D. Y is the centre of the square ABCD. PY = 7.50 m. (a) Given that AB = 3.65 m, show that AY = 2.58 m correct to 3 significant figures. (b) Calculate the length of one of the cables used to support the mast. (c) Calculate APBˆ. (d) The angle of elevation of X from A is 77.0°. (i) Calculate the height, XY of the mast. (ii) Calculate the angle of elevation of X from the midpoint of AB.