Question

Line CF bisect segment ST. All lines bisect a segment at a 90 degree angle, so line CF and segment ST are perpendicular.

Why or why not is this argument valid?

Answer 1

Can anyone walk me through it here? I don't want a direct answer please.

Answer 2

so.. CF bisects ST
are they perpendicular lines?

Answer 3

Yes

Answer 4

If they weren't they would never bisect.

Answer 5

Or collide more like

Answer 6

hmmm was checking the bisect meaning, and it's just to divide in half
but I'd say yes, assuming "ll lines bisect a segment at a 90 degree angle"

Answer 7

So would the answer be "since CF and ST collide they would have to be perpendicular"?

Answer 8

http://www.mathsisfun.com/geometry/bisect.html <--- notice there, is a bisecting line

Answer 9

if you move around the blue line, the red bisector, can bisect without being perpendicular

Answer 10

Meaning when they're perpendicular but right on top of eachother.... so a better answer would be since all lines bisect at 90 degrees and CF bisects ST they would have to be perpendicular correct?

Answer 11

when they're parallel* sorry lol

Answer 12

Thanks :)

Answer 13

hmmm well, if we assume " All lines bisect a segment at a 90 degree angle" is true
then CF and ST are obviously perpendicular

but you can bisect another line, that is, cut it two equal sides WITHOUT being perpendicular

so " All lines bisect a segment at a 90 degree angle" is a fishy statement