#GeometryPuzzle
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catrionaagg.bsky.social
What fraction of the triangle is shaded?
#geometrypuzzle
Part of this triangle has been shaded orange.
May 29, 2025 at 1:20 PM
catrionaagg.bsky.social
The three rectangles are congruent. What fraction of the design is shaded?

#geometrypuzzle
Three partially shaded congruent rectangles, with unshaded triangles connecting some of the corners.
July 5, 2025 at 11:03 AM
catrionaagg.bsky.social
#geometrypuzzle
catrionaagg.bsky.social Catriona Agg @catrionaagg.bsky.social · Mar 29
The two blue angles are equal. What’s the size of the orange angle?
The two shapes that make up the design are a quarter circle and a semicircle. The blue angles are the two marked with solidly coloured sectors. The orange angle is the one marked with an arc and a question mark.
March 29, 2026 at 1:01 PM
catrionaagg.bsky.social
Four quarter circles. What fraction is shaded?
#geometrypuzzle
A design made of four quarter circles, which is partially coloured pink.
May 30, 2025 at 9:39 AM
mathforge.org
Well, that's my weekend sorted!

#geometrypuzzle #mathsky #UKMathsChat
catrionaagg.bsky.social Catriona Agg @catrionaagg.bsky.social · Feb 7
Two regular hexagons inside a rectangle. What fraction of the rectangle is shaded?

I found this #geometrypuzzle in my sketchbook - I drew it last June, but I’m pretty sure I never got round to posting it. Better late than never!
A rectangle with one diagonal drawn in. A regular hexagon sits on the left below the diagonal, with one side vertical against the side of the rectangle, one sloping side lying along the diagonal, and a vertex touching the base of the rectangle. A second regular hexagon sits above the diagonal on the right so that the design has rotational symmetry. Everything inside the rectangle but outside the hexagons is shaded blue.
February 7, 2026 at 10:37 AM
catrionaagg.bsky.social
❤️ Love this ❤️

@mathforge.org has done what I’ve never been organised enough to do myself, and catalogued every #geometrypuzzle I’ve ever posted on social media. It looks amazing!
A screenshot of the puzzle gallery (https://notes.mathforge.org/notes/published/puzzle+gallery) showing lots of tiny geometry colourful puzzles
November 17, 2025 at 6:33 AM
catrionaagg.bsky.social
Three regular hexagons. What’s the diameter of the semicircle?
#geometrypuzzle
Three colourful overlapping hexagons, and a semicircle that goes through their shared vertices.
May 31, 2025 at 11:35 AM
catrionaagg.bsky.social
What fraction of each circle is shaded?

(The 12 points on the circumference are equally spaced, and the other dot is the centre)

I’d love to see how you solved it!

#geometrypuzzle
Six circles, each partially shaded in a different way.
November 17, 2024 at 4:34 PM
ronysarker71.bsky.social
A square and a semicircle make the following figure. What is the red angle?
#geometrypuzzle
June 15, 2025 at 10:25 AM
catrionaagg.bsky.social
Four squares. What’s the angle?

#geometrypuzzle
A big green square and three little white ones. A pink line joins the corner of one the white squares to a corner of the green one.
June 7, 2025 at 8:23 AM
catrionaagg.bsky.social
Four squares. What’s the blue square’s area?

#geometrypuzzle
Two yellow squares both with area 9, an unshaded square, and a blue square whose area is to be found.
June 14, 2025 at 9:41 AM
catrionaagg.bsky.social
Six squares and a quarter circle. The blue square has area 2. What’s the yellow area?

#geometrypuzzle
Six different coloured squares. Five are inside the quarter circle, and the sixth has two vertices on its circumference. The yellow square is the one on the bottom right.
February 16, 2026 at 10:32 AM
catrionaagg.bsky.social
Three regular hexagons. The smallest has area 6. What’s the pink area?

#geometrypuzzle
Two corners of the large yellow hexagon, and one corner of each of the other two hexagons, lie on the circle. All the hexagons are regular.
July 4, 2026 at 8:21 AM
catrionaagg.bsky.social
These triangles are congruent and isosceles. What’s the area of the semicircle?

#geometrypuzzle
A blue triangle on top of a purple one, inside a semicircle. The side length of the purple triangle is 4.
June 21, 2025 at 10:05 AM
catrionaagg.bsky.social
Four quarter circles. What’s the area of the orange one?

#geometrypuzzle
Red, pink and orange quarter circles meet at a point inside a white quarter circle. The red one’s area is 12. What’s the area of the orange one?
June 28, 2025 at 5:46 AM
catrionaagg.bsky.social
One of my favourite puzzles for the weekend!

What’s the area of the toppled square?

#geometrypuzzle
A felt-tip drawing of five squares. On the right is a stack with area 3,12 and 27. On the left is a single square with area 12. And a large square containing a question mark rests at an angle in the centre.
November 23, 2024 at 10:43 AM
ronysarker71.bsky.social
Two rectangles and a square. The length of long side of the red rectangle is 4. What is the total colored area?
#geometrypuzzle
June 13, 2025 at 1:13 AM
catrionaagg.bsky.social
An equilateral triangle inside a regular hexagon. What’s the angle?

#geometrypuzzle
A hand drawn image of a green regular hexagon with a line across the middle. A purple equilateral triangle shared a vertex with the hexagon, and has another vertex on the line across the hexagon’s middle. A blue line from the third vertex of the triangle joins to the next vertex of the hexagon to make an unknown angle with the side of the hexagon.
May 30, 2026 at 10:10 AM
catrionaagg.bsky.social
Seven squares. What’s the angle?
#geometrypuzzle
There are six small pink squares, and a larger tilted purple square which shares ones vertex with the bottom pink square. One vertex of the top pink square lies on the top edge of the purple square. A line from the bottom right vertex of the rightmost pink square makes an unknown angle with the left side of the purple square.
February 28, 2026 at 9:24 AM
catrionaagg.bsky.social
If you’re a #geometrypuzzle fan, it’s definitely worth following @ronysarker71.bsky.social
ronysarker71.bsky.social ronysarker71.bsky.social @ronysarker71.bsky.social · Jun 8
Two isosceles triangle and their top angle is 45 degree. The length of the equal sides are 4. What is the area of red color?
June 11, 2025 at 8:28 PM
mathforge.org
Posted! And categorised.

notes.mathforge.org/notes/publis...

Note: this page links to solutions, but doesn't contain the solution.

#geometrypuzzle
a triangle inside a hexagon in Notes
notes.mathforge.org
May 31, 2026 at 10:15 PM
mathforge.org
If @catrionaagg.bsky.social 's going to start making puzzles again then we'd better have a feed for them.

bsky.app/profile/did:...

#geometrypuzzle #mathsky #UKMathsChat #ITeachMath

(Hope I've made it right ... let me know if not!)
June 7, 2025 at 8:58 PM
mathforge.org
And added to the list ...

notes.mathforge.org/notes/publis...

#geometrypuzzle #mathsky #UKMathsChat #MathsToday
February 19, 2026 at 12:02 PM
catrionaagg.bsky.social
What fraction of this regular octagon is shaded?

#geometrypuzzle
A partially-shaded octagon drawn in pink felt tip pen. If you can imagine a regular octagon with its corners labelled 1 to 8 going around clockwise, draw a line from 1 to 4 and another from 2 to 5. This will create two triangles, which are shaded in.
December 15, 2024 at 3:42 PM
mathforge.org
#geometrypuzzle
matthras.bsky.social Matt Mack @matthras.bsky.social · Jun 10
Shamelessly redrawing on the communal lunch whiteboard at work because someone obviously enjoys solving them 😁 Pic from the last one included.
June 10, 2025 at 6:02 AM