If the lengths of the sides of a triangle are in A.P and the greatest angle is double the smallest, then a ratio of lengths of the sides of this triangle is: (1) $3 : 4 : 5$ (2) $5 : 6 : 7$ (3) $5 : 9 : 13$ (4) $4 : 5 : 6$
If the lengths of the sides of a triangle are in A.P and the greatest angle is double the smallest, then a ratio of lengths of the sides of this triangle is:\\
(1) $3 : 4 : 5$\\
(2) $5 : 6 : 7$\\
(3) $5 : 9 : 13$\\
(4) $4 : 5 : 6$