Last visit was: 11 Aug 2024, 21:03 |
It is currently 11 Aug 2024, 21:03 |

Customized

for You

Track

Your Progress

Practice

Pays

F is the midpoint of AE, and D is the midpoint of CE. Wh
[#permalink]
02 Aug 2017, 08:37

1

Expert Reply

11

Bookmarks

Question Stats:

Attachment:

#GREpracticequestion F is the midpoint of AE, and D is the midpoint of CE.jpg [ 20.98 KiB | Viewed 9130 times ]

F is the midpoint of AE, and D is the midpoint of CE.

Which of the following statements MUST be true?

Indicate all such statements.

❑ FD is parallel to AC.

❑ The area of triangle DEF equals the area of triangle CDF.

❑ The area of triangle ABF is less than the area of triangle DEF.

❑ Angle AFB equals angle BFC.

❑ The area of triangle ACE equals AC x BF.

Re: F is the midpoint of AE, and D is the midpoint of CE. Wh
[#permalink]
24 Sep 2017, 08:34

1

Any hint for this question?

Re: F is the midpoint of AE, and D is the midpoint of CE. Wh
[#permalink]
25 Sep 2017, 02:34

3

Expert Reply

A is right

Because DE is \(\frac{1}{2}\) of CE and FE is \(\frac{1}{2}\) of AE (i.e., corresponding sides have proportional lengths), and angle DEF is shared between /the two triangles, you can see that triangles ACE and FDE must be similar. Similar triangles have the further property that corresponding angles are of equal measure. Thus, for example, angle DFE equals angle CAE, and so FD is parallel to AC.

B is right

Looking at the two smaller triangles in the right half of the figure, you can see that triangle CD F and triangle DEF have collinear and equal “bases” (CD and DE), and share their third vertex (F), which is some fixed distance away from

CE. Because CE is comprised of bases CD and DE of triangles CD F and DEF, respectively, the two triangles have the same height. Because CDF and DEF have equal bases and the same height, they must have the same area. (For a similar reason, triangles ACF and FCE must have equal areas; more on that later.)

Choice E is right

Because triangles ACF and FCE must have equal areas as indicated above, you can see that the area of triangle ACE must be twice that of triangle ACF. Note that FD is parallel to AC due to (true) choice (A), and BF is perpendicular toFD. Therefore, BF must be perpendicular to AC as well. Put differently, AC can be regarded as the base, and BF the height, of triangle ACF. The area of triangle ACF equals ^ times AC x BF. The area of triangle ACE, which is twice that of ACF, must therefore equal AC x BF.

Because DE is \(\frac{1}{2}\) of CE and FE is \(\frac{1}{2}\) of AE (i.e., corresponding sides have proportional lengths), and angle DEF is shared between /the two triangles, you can see that triangles ACE and FDE must be similar. Similar triangles have the further property that corresponding angles are of equal measure. Thus, for example, angle DFE equals angle CAE, and so FD is parallel to AC.

B is right

Looking at the two smaller triangles in the right half of the figure, you can see that triangle CD F and triangle DEF have collinear and equal “bases” (CD and DE), and share their third vertex (F), which is some fixed distance away from

CE. Because CE is comprised of bases CD and DE of triangles CD F and DEF, respectively, the two triangles have the same height. Because CDF and DEF have equal bases and the same height, they must have the same area. (For a similar reason, triangles ACF and FCE must have equal areas; more on that later.)

Choice E is right

Because triangles ACF and FCE must have equal areas as indicated above, you can see that the area of triangle ACE must be twice that of triangle ACF. Note that FD is parallel to AC due to (true) choice (A), and BF is perpendicular toFD. Therefore, BF must be perpendicular to AC as well. Put differently, AC can be regarded as the base, and BF the height, of triangle ACF. The area of triangle ACF equals ^ times AC x BF. The area of triangle ACE, which is twice that of ACF, must therefore equal AC x BF.

Re: F is the midpoint of AE, and D is the midpoint of CE. Wh
[#permalink]
27 Jun 2018, 08:54

1

Hello guys, any hint why choices C and D are false?

Re: F is the midpoint of AE, and D is the midpoint of CE. Wh
[#permalink]
28 Jun 2018, 02:21

Expert Reply

if you redraw the figure as follow, then C and D not necessarily are true.

triangle.png [ 35.83 KiB | Viewed 9519 times ]

Attachment:

triangle.png [ 35.83 KiB | Viewed 9519 times ]

Re: F is the midpoint of AE, and D is the midpoint of CE. Wh
[#permalink]
04 Aug 2019, 15:17

For answer choice E, how do you know triangles ACF and FCE are equal in area ?

Thanks in advance!

Thanks in advance!

Re: F is the midpoint of AE, and D is the midpoint of CE. Wh
[#permalink]
04 Aug 2019, 16:37

Expert Reply

Because CE is comprised of bases CD and DE of triangles CD F and DEF, respectively, the two triangles have the same height. Because CDF and DEF have equal bases and the same height, they must have the same area. (For a similar reason, triangles ACF and FCE must have equal areas; more on that later.)

Read carefully.

Ask if you do need further explanations. Sir

Regards

Read carefully.

Ask if you do need further explanations. Sir

Regards

Re: F is the midpoint of AE, and D is the midpoint of CE. Wh
[#permalink]
09 Dec 2019, 05:17

1

Carcass wrote:

A is right

Because DE is \(\frac{1}{2}\) of CE and FE is \(\frac{1}{2}\) of AE (i.e., corresponding sides have proportional lengths), and angle DEF is shared between /the two triangles, you can see that triangles ACE and FDE must be similar. Similar triangles have the further property that corresponding angles are of equal measure. Thus, for example, angle DFE equals angle CAE, and so FD is parallel to AC.

B is right

Looking at the two smaller triangles in the right half of the figure, you can see that triangle CD F and triangle DEF have collinear and equal “bases” (CD and DE), and share their third vertex (F), which is some fixed distance away from

CE. Because CE is comprised of bases CD and DE of triangles CD F and DEF, respectively, the two triangles have the same height. Because CDF and DEF have equal bases and the same height, they must have the same area. (For a similar reason, triangles ACF and FCE must have equal areas; more on that later.)

Choice E is right

Because triangles ACF and FCE must have equal areas as indicated above, you can see that the area of triangle ACE must be twice that of triangle ACF. Note that FD is parallel to AC due to (true) choice (A), and BF is perpendicular toFD. Therefore, BF must be perpendicular to AC as well. Put differently, AC can be regarded as the base, and BF the height, of triangle ACF. The area of triangle ACF equals ^ times AC x BF. The area of triangle ACE, which is twice that of ACF, must therefore equal AC x BF.

Because DE is \(\frac{1}{2}\) of CE and FE is \(\frac{1}{2}\) of AE (i.e., corresponding sides have proportional lengths), and angle DEF is shared between /the two triangles, you can see that triangles ACE and FDE must be similar. Similar triangles have the further property that corresponding angles are of equal measure. Thus, for example, angle DFE equals angle CAE, and so FD is parallel to AC.

B is right

Looking at the two smaller triangles in the right half of the figure, you can see that triangle CD F and triangle DEF have collinear and equal “bases” (CD and DE), and share their third vertex (F), which is some fixed distance away from

CE. Because CE is comprised of bases CD and DE of triangles CD F and DEF, respectively, the two triangles have the same height. Because CDF and DEF have equal bases and the same height, they must have the same area. (For a similar reason, triangles ACF and FCE must have equal areas; more on that later.)

Choice E is right

Because triangles ACF and FCE must have equal areas as indicated above, you can see that the area of triangle ACE must be twice that of triangle ACF. Note that FD is parallel to AC due to (true) choice (A), and BF is perpendicular toFD. Therefore, BF must be perpendicular to AC as well. Put differently, AC can be regarded as the base, and BF the height, of triangle ACF. The area of triangle ACF equals ^ times AC x BF. The area of triangle ACE, which is twice that of ACF, must therefore equal AC x BF.

Choice E is right

Because triangles ACF and FCE must have equal areas as indicated above, you can see that the area of triangle ACE must be twice that of triangle ACF. Note that FD is parallel to AC due to (true) choice (A), and BF is perpendicular toFD. Therefore, BF must be perpendicular to AC as well. Put differently, AC can be regarded as the base, and BF the height, of triangle ACF. The area of triangle ACF equals ^ times AC x BF. The area of triangle ACE, which is twice that of ACF, must therefore equal AC x BF.

Edited : (The last line will be---) The area of triangle ACF equals = \(\frac{1}{2}\) * AC x BF. The area of triangle ACE, which is twice that of ACF, must therefore equal AC x BF.

Extended: ACF = \(\frac{1}{2}\) * AC x BF

=> 2 *ACF = AC x BF

so, ACE = AC x BF (as we know triangle ACE is twice of triangle ACF)

Re: F is the midpoint of AE, and D is the midpoint of CE. Wh
[#permalink]
14 Jul 2024, 08:28

Hello from the GRE Prep Club BumpBot!

Thanks to another GRE Prep Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.

Thanks to another GRE Prep Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.

gmatclubot

Re: F is the midpoint of AE, and D is the midpoint of CE. Wh [#permalink]

14 Jul 2024, 08:28
Moderators:

Multiple-choice Questions — Select One or More Answer Choices |
||

## Hi Generic [Bot],Here are updates for you: |