part 1
<FED = <GEN = 60 (vertical angles)
<GEN + <NED = 180(supplementary angles)
<DEN = 180 - 60 = 120
part 2
AD = 10
DG = twice AD = 2 x 10 = 20
AG = AD + DG = 10 + 20 = 30
part 3
<FED = <GEN (vertical angles)
<GED (straight angle)
2 acute angles: <FED and <CDA
part 4
A linear pair of angles is formed when two lines intersect. Two angles are said to be linear if they are adjacent angles formed by two intersecting lines.
example:
<GNM and <MNK
<GNM + <MNK = 180
