12 of 23 Items .... Type: Geometry Snacks

Problems, Questions, and Puzzles to spark discussion and argument in the maths classroom.

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Consider a normal, everyday clock face.

If the MINUTE hand is on 2, and the hour hand and minute hand make an acute angle, what time could it be?

If the MINUTE hand is on 8, and the hour hand and minute hand make an obtuse angle, what time could it be?


.: [MS Math], [internet], [Geometry Snacks].

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What is the red area?

The two vertices of the square are the centers of two tangent and congruent circles. If the length of a side is \( 8\sqrt{2} \), what is the area of the red part peeping out?

Here is another question: Does it matter if the circles are congruent, as long as they're tangent and the centers are at the vertices of the square?


.: [GEOM], [David Marain], [Geometry Snacks].

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What percent is orange? Green?


.: [PREALG], [Dan Anderson], [Geometry Snacks].

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W

The Salinon was first introduced in the Book of Lemmas, a work attributed to Archimedes


.: [GEOM], [Cliff Pickover], [Geometry Snacks].

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What is the area of the whole hexagonal shape?
Can your students generalize this result?


.: [GEOM], [Cliff Pickover], [Geometry Snacks].

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Last question with this visual:

How could you draw the inscribed semicircle (area = \( \pi \)) so that the rectangle is of maximum size?




.: [GEOM], [David Marain], [Geometry Snacks].

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This problem was posed on Twitter the other day.


A semicircle is inscribed in a rectangle. If the area of the semicircle is pi, what's the area of the rectangle?

My question yesterday was ... how could you draw the inscribed semicircle in a way that gives a rectangle of a very different (and larger) area?

My question today is, given the arrangement below, what points did I choose that had integer coordinates? I chose a larger semicircle - for convenience - how big was it?




.: [GEOM], [David Marain], [Geometry Snacks].

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This problem was posed on Twitter the other day.

A semicircle is inscribed in a rectangle. If the area of the semicircle is pi, what's the area of the rectangle?

My question is ... how could you draw the inscribed semicircle in a way that gives a rectangle of a very different (and larger) area?


.: [GEOM], [David Marain], [Geometry Snacks].

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What combinations of addition or subtraction of figures could you use to find the area of the white?



.: [GEOM], [T.R.Milne], [Geometry Snacks].

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.: [GEOM], [Ed Southall], [Geometry Snacks].

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What's the perimeter?



.: [MS Math], [Ed Southall], [Geometry Snacks].

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Two 3-4-5 triangles sit on straight line AB, as do 2 points that form a regular hexagon. What is the area of the pink shaded region?


.: [GEOM], [Ed Southall], [Geometry Snacks].