geometry problem

by kjhgyuio, Apr 20, 2025, 10:21 PM

........
Attachments:

2024 MathCounts Nationals Target #2

by UberPiggy, Apr 19, 2025, 11:32 PM

I know target #2 is supposed to be easy but I literally cannot figure out how to do this one. Could someone help please?

Trapezoid $ABCD$ has parallel bases $AB$ and $CD$, $M$ is the midpoint of side $AD$ and $m \angle{BCM} = 90^{\circ}$. If $AB = BC = 7$ cm and $CD = 18$ cm, what is $BM$? Express your answer in simplest radical form.

The answer is answer
This came with a diagram but I'm too lazy to attach it here

Weird Similarity

by mithu542, Apr 18, 2025, 6:03 PM

Is it just me or are the 2023 national sprint #21 and 2025 state target #4 strangely similar?
2023 Natioinal Sprint #21 wrote:
A right triangle with integer side lengths has perimeter $N$ feet and area $N$ ft^2. What is the arithmetic mean of all possible values of $N$?
2025 State Target #4 wrote:
Suppose a right triangle has an area of 20 cm^2 and a perimeter of 40 cm. What is
the length of the hypotenuse, in centimeters?
This post has been edited 2 times. Last edited by mithu542, Apr 18, 2025, 6:04 PM

Geometry Transformation Problems

by ReticulatedPython, Apr 17, 2025, 3:46 PM

Problem 1:
A regular hexagon of side length $1$ is rotated $360$ degrees about one side. The space through which the hexagon travels during the rotation forms a solid. Find the volume of this solid.

Problem 2:

A regular octagon of side length $1$ is rotated $360$ degrees about one side. The space through which the octagon travels through during the rotation forms a solid. Find the volume of this solid.

Source:Own

Hint

Useful Formulas
This post has been edited 11 times. Last edited by ReticulatedPython, Apr 21, 2025, 3:33 PM

Geometry 7.3 tangent

by luciazhu1105, Apr 9, 2025, 10:11 PM

I have trouble getting tangents and most things in the chapter, so some help would be appreciated!

Wrong Answers Only Pt.2

by MathRook7817, Apr 9, 2025, 5:49 PM

Problem: What is the area of a triangle with side lengths 13,14, and 15?
WRONG ANSWERS ONLY!

other one got locked for some reason

A geometry problem

by Deomad123, Apr 8, 2025, 7:20 PM

Let $ABCD$ be an cyclic quadrilateral with $AB=8cm$,$BC=7cm$,$CD=6cm$ and $DA=5cm$ Find:$\frac{AC}{BD}$

Good resources for Mathcounts and AMCs

by HoneyHap, Apr 6, 2025, 9:10 PM

Hi people!
I have been and aops user for only a few months and not an active one either, just a user checking other posts and competitions. This is actually my first post. I am in 7th grade and only this year I have actually started locking in on competition math, before that, I didn’t really care about Mathcounts and AMCs. So, I hone my problem-solving skills by lightly doing some math problems. I have signed up for a lot of math competitions this month and am struggling to prepare properly with the resources I have. Do you guys have any resources you use to prepare for math competitions and that are actually helpful to use to prepare for competitions in a short amount of time. I am looking for resources that first teach you stuff and give you problems, like guided notes and handouts. I have few aops books like “Competition Math for Middle School” and “Intermediate Algebra”, but they’re not enough. I have learnt Algebra 1 and started doing high school geometry and a bit of Algebra 2 at home. Do let me know if you have any suggestions!

1000th Post!

by PikaPika999, Apr 5, 2025, 11:32 PM

When I had less than 25 posts on AoPS, I saw many people create threads about them getting 1000th posts. I thought I would never hit 1000 posts, but here we are, this is my 1000th post.

As a lot of users like to do, I'll write my math story:

Daycare
Preschool
Kindergarten
First Grade
Second Grade
Third Grade
Fourth Grade
Fifth Grade
Sixth Grade

In conclusion, AoPS has helped me improve my math. I have also made many new friends on AoPS!

Finally, I would like to say thank you to all the new friends I made and all the instructors on AoPS that taught me!

Minor side note, but

Area of Polygon

by AIME15, Jan 12, 2009, 3:06 AM

The area of polygon $ ABCDEF$, in square units, is

[asy]draw((0,0)--(4,0)--(4,9)--(-2,9)--(-2,4)--(0,4)--cycle);
label("A",(-2,9),NW);
label("B",(4,9),NE);
label("C",(4,0),SE);
label("D",(0,0),SW);
label("E",(0,4),NE);
label("F",(-2,4),SW);
label("5",(-2,6.5),W);
label("4",(2,0),S);
label("9",(4,4.5),E);
label("6",(1,9),N);
label("All angles in this diagram are right.",(0,-3),S);[/asy]

\[ \textbf{(A)}\ 24 \qquad
\textbf{(B)}\ 30 \qquad
\textbf{(C)}\ 46 \qquad
\textbf{(D)}\ 66 \qquad
\textbf{(E)}\ 74
\]

It's not just good - it's revolutionary!

avatar

liberator
Shouts
Submit
  • whoa....

    by bachkieu, Jan 31, 2025, 1:40 AM

  • hello...

    by ethan2011, Jul 4, 2024, 5:13 PM

  • 2024 shout ftw

    by Shreyasharma, Feb 19, 2024, 10:28 PM

  • time flies

    by Asynchrone, Dec 13, 2023, 9:29 PM

  • first 2023 shout :D

    by gracemoon124, Aug 2, 2023, 4:58 AM

  • offline.................

    by 799786, Dec 27, 2021, 7:08 AM

  • YOU SHALL NOT PASS! - liberator

    by OlympusHero, Aug 16, 2021, 4:10 AM

  • Nice Blog!

    by geometry6, Jul 31, 2021, 1:39 PM

  • First shout out in 2021 :D

    by Aimingformygoal, May 31, 2021, 4:23 PM

  • indeed a pr0 blog :surf:

    by Kanep, Dec 3, 2020, 10:46 PM

  • pr0 blog !!

    by Hamroldt, Dec 2, 2020, 8:32 AM

  • niice bloog!

    by Eliot, Oct 1, 2020, 3:27 PM

  • nice blog :o

    by fukano_2, Aug 8, 2020, 7:49 AM

  • Nice blog :)

    by Feridimo, Mar 31, 2020, 9:29 AM

  • Very nice blog !

    by Kamran011, Oct 31, 2019, 5:48 PM

56 shouts
Tags
About Owner
  • Posts: 95
  • Joined: May 28, 2014
Blog Stats
  • Blog created: Aug 13, 2014
  • Total entries: 46
  • Total visits: 38186
  • Total comments: 43
Search Blog
a