I have two angles (EAF and JAD) that share A as a vertex. The both look vertical. The book wants me to prove that the are vertical. There are no markings.
2007-09-05 11:27:07 · 8 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
According to the Vertical Angles theorem if 2 angles are vertical angles then they are congruent...
2007-09-05 11:42:57 · answer #1 · answered by master 2 · 0⤊ 0⤋
By verical I assume you mean that they look like the vertical angles you get when two straight lines intersect. If this is the case, it meets your description that they share the common vertex A.
But just because they look like vertical angles is no proof that they are indeed verical angles. There is no way to prove it with the info you have given. You would have to prove that ED and FJ are straight lines intersecting at A.
Are you sure you have given all the info?
2007-09-05 18:41:21 · answer #2 · answered by ironduke8159 7 · 0⤊ 0⤋
the definition of vertical angles states:
2 angles are vertical angles iff the sides of one angle are opposite rays to the sides of the other, you can't prove definitions.
if it is asking to prove that angles EAF and JAD are equal (or congruent depends on your teacher/book)
to make it easier, angle EAF is angle 1, FAJ is angle 2, and JAD is angle 3.
Given: angle 1 and angle 3 are vertical angles
Prove: angle1=angle2
1. angle 1 and angle 2 are vertical angles (given)
2. the sides of angle 1 are opposite rays to the sides of angle 3 (definiation of vertical angles)
3. angle1 and angle 2 are a linear pair; angle 2 and angle 3 are a linear pair (definiation of a linear pair "2 angles are a linear pair if they have a common side and their other sides are opposite rays")
4. angle 1 and angle 2 are supplementary; angle 2 and angle 3 are supplementary (the angles in a inear pair are supplementary)
5. angle 1=angle 3 (supplements of the same angle are equal/congruent)
2007-09-05 18:41:59 · answer #3 · answered by Brian 4 · 0⤊ 0⤋
Vertical angles are congruent.
I think it's called the vertical angle theorem, but I'm not positive.
2007-09-05 18:30:01 · answer #4 · answered by Anonymous · 0⤊ 0⤋
Ya, if they share a mutual intersecting point i think that proves it's vertical angles
2007-09-05 18:32:01 · answer #5 · answered by Anonymous · 0⤊ 0⤋
uhh find the angle and if it is 90 degrees up its vertical.
2007-09-05 18:29:58 · answer #6 · answered by § Elijah § 3 · 0⤊ 0⤋
use a protracter
2007-09-05 18:32:43 · answer #7 · answered by aeagle1996 2 · 0⤊ 0⤋
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2007-09-05 18:31:21 · answer #8 · answered by Dried_Squid 2 · 0⤊ 0⤋