Ask your own question, for FREE!
Mathematics 8 Online
OpenStudy (icalibear):

What is the measure of AC?

OpenStudy (icalibear):

|dw:1355694152223:dw|

OpenStudy (anonymous):

Two quick questions on that: 1. Are any of the lines parallel that you know of? 2. Do you know if any of the points B,D, or F bisect the line segments they're on?

OpenStudy (icalibear):

oh. B bisects AC

OpenStudy (anonymous):

Ok. I'll see if I can find something for you...

OpenStudy (icalibear):

D bisects EC and F bisects AE

OpenStudy (icalibear):

ok

OpenStudy (icalibear):

is the answer 38

OpenStudy (anonymous):

Not necessarily. Only if the triangle is equilateral or isosceles (with EC and AC being the two congruent sides).

OpenStudy (icalibear):

Well it doesn't exactly tell me that all it says is that points B, D, and F are midpoints of the sides of ^ACE, EC = 38 and DF = 16. But it looks like an equilateral triangle.

OpenStudy (anonymous):

It's not equilateral. If it were then either FD would be 19 or EC would be 32

OpenStudy (icalibear):

Well if its not an equilateral triangle what do i do to find AC?

OpenStudy (anonymous):

Ah-hah! If we consider the triangles EFD and ACE, we see that they both share the FED angle. Then, since we know that DF bisects both AE and EC, we know that EF = 2 AE and ED = 2 EC. Thus we can say that the triangles are similar. Then we can say \[\frac{ ED }{ EC }=\frac{ FD }{ AC }\]Substituting in your know values you get \[\frac{ 19 }{ 38 }=\frac{ 16 }{ AC }\]So then you get \[AC=\frac{ 16 \times 38 }{ 19 }\]

OpenStudy (icalibear):

so its 32?

OpenStudy (anonymous):

Yes

OpenStudy (icalibear):

ok thank you i just didnt get tht

OpenStudy (icalibear):

:P

Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!
Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!