Question

help?


write an indirect proof to show that opposite angles of a parallelogram are congruent.

Answer 1

@perl are you going to help me?

Answer 2

we want to prove that

Answer 3

my draw button keeps dying, one moment

Answer 4

okay

Answer 5

@perl but how do I put that information into a sentence?

Answer 6

we want to prove that <A = <C and <B = <D

Assume the opposite, that at least one of those two pairs of angles are not congruent.

So without loss of information we can assume that
<A not equal to <C.

AB is a transverse to AD and BC
<A+<B=180 degrees (consecutive angles with parallel lines)

BC is a transverse to AB and CD
<B+<C=180 degrees

<A+<B=<B+<C
<A=<C (subtraction of equal numbers)

But we assumed <A is not equal to <C. contradiction!

Answer 7

thanks can you help me with another one? please @perl

Answer 8

ok

Answer 9

square RSTU is constructed with line PQ drawn through its center. if the square is dilated using a scale factor of 1/2 and a line is drawn thought the center of the new dilated figure,what relationship will the new line have with line PQ? explain your reasoning. @perl

Answer 10

do you have a diagram of this

Answer 11

no that's the whole question