this post was submitted on 08 Jun 2025
899 points (92.0% liked)

memes

15473 readers
4507 users here now

Community rules

1. Be civilNo trolling, bigotry or other insulting / annoying behaviour

2. No politicsThis is non-politics community. For political memes please go to !politicalmemes@lemmy.world

3. No recent repostsCheck for reposts when posting a meme, you can only repost after 1 month

4. No botsNo bots without the express approval of the mods or the admins

5. No Spam/AdsNo advertisements or spam. This is an instance rule and the only way to live.

A collection of some classic Lemmy memes for your enjoyment

Sister communities

founded 2 years ago
MODERATORS
 
(page 2) 50 comments
sorted by: hot top controversial new old
[–] PP_BOY_@lemmy.world 20 points 3 days ago (2 children)

Learned this one in 6th grade geometry: drawing a square in thr corner doesn't make it 90°

[–] Mr_Fish@lemmy.world 12 points 3 days ago

But these are all right angles, as long as the two arcs are centered on the same point as the intersection of the two straight lines.

[–] Zagorath@aussie.zone 4 points 3 days ago

drawing a square in thr corner doesn’t make it 90°

No, it doesn't, but it does mean that, for the purposes of your 6th grade geometry question, you can assume the angle is a right angle. Even if it visible looks like 45°, if they put a square there, that's 90.

More to the point though, a radius of a circle always meets the circumference at 90 degrees. All the squares in this problem are doing is telling you "this line, if it were continued, would be the radius of the incomplete circle".

[–] TORFdot0@lemmy.world 7 points 2 days ago
[–] DeusUmbra@lemmy.world 15 points 3 days ago

Dammit Diogenes, this is why we don't allow you in the geometry class anymore.

[–] jim3692@discuss.online 16 points 3 days ago (7 children)

Solution:

Explanation:

  1. in order for the straight lines to be 90 deg with the circles, they must be radii of circles with same central point

  2. the length of an arc is defined as c = r * θ (where r is the radius, and θ is the angle)

  3. we define the inner circle with radius r₁ and its arc L₁ = r₁ * θ₁

  4. we define the outer circle with radius r₂ and its arc L₂ = r₂ * θ₂

  5. Because of (1), θ₁ + θ₂ = 2π

  6. To create the shape, L₁ = L₂ = r₂ - r₁

If you start replacing and solving, you will get a 2nd grade quadratic, which has a positive and a negative solution. The positive solution is that magic number.

load more comments (7 replies)
load more comments
view more: ‹ prev next ›