min lenght of fishing pole, 6-7-8 pool (2019 Indonesia LuMaT Final SMP p3)

Art of Problem Solving

AoPS Online

High School Math Grades 9-12, Ages 13-18

Grades 9-12, Ages 13-18

3 M G

BBookmark VNew Topic kLocked

High School Math Grades 9-12, Ages 13-18

Grades 9-12, Ages 13-18

3 M G

BBookmark VNew Topic kLocked

No tags match your search

M

min lenght of fishing pole, 6-7-8 pool (2019 Indonesia LuMaT Final SMP p3)

G H J

Reveal topic tags

L

G H BBookmark kLocked kLocked NReply

The post below has been deleted. Click to close.

This post has been deleted. Click here to see post.

30629 posts

#1 h Dec 11, 2020, 4:54 AM

Y by

Mrs Ippi will fish in a triangular pond of side length $6,7,8$ with a fishing pole of length $t$ . What is the mininal value of $t$ , so that wherever the fish inside the pool is located, Mrs. Ippi can throw the bait from outside of the point on top of the fish?

This post has been edited 1 time. Last edited by parmenides51, Dec 11, 2020, 4:55 AM

Z K Y

The post below has been deleted. Click to close.

This post has been deleted. Click here to see post.

8219 posts

#2 h Dec 11, 2020, 5:03 AM • 1 Y

Y by Mango247

I believe this is the inradius, which can be easily calculated with heron's as $\frac{\sqrt{15}}{2}$

This post has been edited 1 time. Last edited by natmath, Dec 11, 2020, 7:47 AM

Z K Y

The post below has been deleted. Click to close.

This post has been deleted. Click here to see post.

1703 posts

#3 h Dec 11, 2020, 7:24 AM

Y by

@above, I disagree. I got the inradius to be $\frac {\sqrt {15}}{2}$
herons

This post has been edited 1 time. Last edited by JustinLee2017, Dec 11, 2020, 7:26 AM

Z K Y

The post below has been deleted. Click to close.

This post has been deleted. Click here to see post.

8219 posts

#4 h Dec 11, 2020, 7:48 AM

Y by

Oof, I make too many sillies :oops_sign:

:oops_sign:

Z K Y

The post below has been deleted. Click to close.

This post has been deleted. Click here to see post.

23531 posts

#5 h Dec 11, 2020, 6:35 PM

Y by

Wait why is this just the inradius? Suppose she is on vertex A and the fish is at a different vertex. Then it won't work.

Z K Y

The post below has been deleted. Click to close.

This post has been deleted. Click here to see post.

8219 posts

#6 h Dec 11, 2020, 6:52 PM

Y by

franzliszt wrote:

Wait why is this just the inradius? Suppose she is on vertex A and the fish is at a different vertex. Then it won't work.

I assumed that she is free to choose any location outside the pool. Isn't that what the question is asking, or am I interpreting wrongly?

This post has been edited 1 time. Last edited by natmath, Dec 11, 2020, 6:52 PM

Z K Y

The post below has been deleted. Click to close.

This post has been deleted. Click here to see post.

23531 posts

#7 h Dec 11, 2020, 7:01 PM

Y by

Oh wait I think I misunderstood. Your interpretation sounds correct.

Z K Y

N Quick Reply

G

H

=

© 2025 AoPS Incorporated

a