In this model, the proper bonding angles are linear, so they are 180 degrees as shown. The unshared electron pairs of oxygen are repelling each other in all instances. Also, the actual arrangement of which side the hydroxide groups go on is key relative to the carbon chain. For D-Glucose, it is specific the hydoxide groups must be connected on the right of the 2nd, 4th, and 5th carbons, starting from the top. Also, at the third carbon, there must be a hydroxide group on the left. This is essential in the molecule being D-Glucose and reflecting light left to right, as opposed to L-Glucose, which woul be a mirror image and reflect light towards the left.
In this model, the optimum bonding angle is 109.5 degrees, however due to constraints of geometry, not every bonding angle can be such, so some may be smaller or larger. The unshared electron pairs of oxygen are once again repelling each other. The color key is consistent throughout the drawings with that of the Lewis Structures, with green representing carbon, yellow representing oxygen, red representing hydrogen, and black representing bonds.