A series of figures are given which can be grouped into

A series of figures are given which can be grouped into classes. Select the group into which the figures can be classified from the given responses.

1. 1, 6, 9; 2, 4, 7; 3, 5, 8
2. 1, 6, 9; 3, 4, 7; 2, 5, 8
3. 2, 6, 9; 1, 4, 3; 5, 7, 8
4. 2, 9, 3; 1, 8, 7; 4, 5, 6

As we can say that ,
Figures 1, 6 and 9 ⇒ Obtuse angles
Figures 2, 4, and 7 ⇒ Acute angles
Figures 3, 5 and 8 ⇒Right angles