(Please do keep in mind that when you name angles, the first and third letters can be switched. So if you have <COA and I say <AOC, they are the same thing as long as O is the second letter)
2a) Complementary means the sum of the angles is 90°. Since <COA is 90°, <COB and <BOA are complementary.
2b) Supplementary means the sum of the angles is 180°. Since 180° is a straight line, there are three angles including that angle to make 180°. So in addition to <BOC, your answer would be <BOA and <COD.
2c) Vertical angles are across from each other. The angle across from <BOA is <DOE.
3a) 90°. There's a little square there letting you know it's 90°
3b) 51°. Since <CBF and <CBE are complementary, you would subtract 39 from 90.
3c) 17°. Since <DBE and <ABE are complementary, you subtract 73 from 90.
4) Keep in mind that ray BO is a bisector of <AOC, in other words, the ray splits the angle in half. So <AOB is congruent to <BOC. So solve for x:
x+3=2x+11
3=x+11
x=-8
Now plug in x for either angle
8+3= 11
So that means <AOB and <BOC both equal 11°.
To find <AOC, double that.
<AOC equals 22°.
