Question

I am not sure about this

http://prntscr.com/35aoil

Answer 1

A bit challenging...

Answer 2

What do you know about the "vertical angles" at vertex C?

Answer 3

isn't it a side angel?

Answer 4

when two lines cross the angles that are formed that are opposite to each other are called "vertical" angles. They have a certain characteristic with respect to their magnitude. What is it?

Answer 5

Hint: steps 2 and 3 of the proof establish that two of the three corresponding angles of the two triangles are congruent. The vertical angles are the third pair of corresponding angles.

Answer 6

I am not quite sure

Answer 7

Vertical angles Theorem: vertical angles are always congruent.
if you like, check out: http://hotmath.com/hotmath_help/topics/vertical-angles-theorem.html
So what do we know about the relationship between the corresponding angles between the two triangles?

Answer 8

we know that there similar

Answer 9

The triangles are similar since _____.

Answer 10

they have Angle-Angle similarity

Answer 11

Yes. So your answer in the figure you provided is correct. The reason that the triangles are similar is that "all corresponding angles are congruent."

Answer 12

yeah i noticed that hehe

Answer 13

btw, this is a very good reference site: http://www.mathopenref.com

Answer 14

thanks i mostly use http://www.mathsisfun.com/triangle.html

Answer 15

http://www.mathsisfun.com/index.htm

Answer 16

that's a good one too, but mathpenref is really good for geometry.

Answer 17

oh alright thanks i 'll try it

Answer 18

ok, later!