Vertical Angles Proof Math
By the symmetric property of equality b a.
Vertical angles proof math. When two lines intersect the opposite angles form vertical angles or vertically opposite angles. This angle is equal to this vertical angle is equal to its vertical angle right over here and that this angle is equal to this angle that is opposite the intersection right over here. Note that m a means measure of angle a. Therefore by the definition of congruent angles it follows that b a.
Here is a paragraph proof for the symmetric property of angle congruence. Finally angle 3 and angle 6 are congruent vertical angles so angle 6 must be 145 as well. Now plug 5 and 15 into the angle expressions to get four of the six angles. Vertical angles are congruent in other words they have the same angle measuremnt or size as the diagram below shows diagram 1 m angle x in digram 1 is 157 circ since its vertical angle is 157 circ.
They are called vertical angles because they share the same vertex. Use this figure for the proof. We are given that a b. Proof of the vertical angles theorem.
M b m c 180 degrees. Notice also that x and y are supplementary angles i e. Prove m a m b. What we have proved is the general case because all i did here is i just did two general intersecting lines i picked a random angle and then i proved that it is equal to the angle that is vertical to it.
By the definition of congruent angles a b. By the angle addition postulate m a m c 180 degrees. A and b are vertical angles. Vertical angles are equal.
Vertical angles theorem the theorem. Y 3 5 y 15. The vertical angle theorem states that. The vertical angles theorem states that the opposite vertical angles of two intersecting lines are.
Often you will see proofs end with the. Y 3 x. Their sum is 180.