Shape	Bond angle
A) Tetrahedral	1) $180°$
B) Linear	2) $120°$
C) Octahedral	3) $109°{28}^1$
D) Trigonal Planar	4) $90°$

In tetrahedral molecule, the central atom undergoes ${\text{sp}}^3$ hybridization. So the bond angle is $109°{28}^1$. 

In linear molecule, the central atom undergoes $\text{sp}$ hybridization.  So the bond angle is $180°$.

In octahedral molecule, the central atom undergoes ${\text{sp}}^3{\text{d}}^{\text{2}}$ hybridization.  So the bond angle is $90°$.

In trigonal planar molecule, the central atom undergoes ${\text{sp}}^2$ hybridization.  So the bond angle is $120°$.