#### Answer

a) it is given
b) $m\angle V$
c)180
d) Division
e) right

#### Work Step by Step

a) This is stated in the problem, so is called "given".
b) This is the definition of congruent angles.
c) The measures of supplementary angles sum to 180.
d) Each side of the equation was divided by 2.
e) A right angle is an angle that measures $90^o$.