if

Question

if <A and <B are vertical angles, must <A=<b?

anonymous · Answer

yes vertical angles will always be equal to each other

anonymous · Answer

thank you @Koa  :)

mathstudent55 · Answer

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This is the reason why vertical angles are congruent.

In the figure above, lines m and n intersect forming vertical anlges 1 and 2.

Angle 1 is supplementary to angle 3, or m<1 + m<3 = 180.
Angle 2 is supplementary to angle 3, or m<2 + m<3 = 180.

Use substitution to get
m<1 + m<3 = m<2 + m<3

Now subtract m<3 from both sides, and you get
m<1 = m<2

From here you see that it makes no difference what the measures of the angles are; vertical angles are congruent.

anonymous · Answer

^^ better response

anonymous · Answer

than you @mathstudent55  its very helpful :)

mathstudent55 · Answer

wlcm

anonymous · Answer

my next question is
given: <a=<b,<b=c
prove: <A=<c
proof: ?

anonymous · Answer

who can help me in my question :) ?In the image below, a line was drawn horizontally through the center of ABCD. If ABCD was dilated using a scale factor of 2 and a line was drawn horizontally through the center of the dilated figure, what would you notice about the two lines? Explain your answer using complete sentences.