Answer:
C
Explanation:
(a)the sum of a vertical is always 180 this is true for liner angles not vertical angles.
(b) vertical angles combine to form a strategist angle, a straight angle is 180 so like in answer a this is talking about a liner angle not a vertical angle.
(c) this is ALWAYS true for vertical angles because, if they are not well it wouldn't be a vertical angle than.
(d) the sum of vertical angles is always 90 this is wrong its talking about a complementary angle not a vertical angle.