Pythagoras' theorem
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problemRectangular Pyramids
Is the sum of the squares of two opposite sloping edges of a rectangular based pyramid equal to the sum of the squares of the other two sloping edges? -
problemXtra
Find the sides of an equilateral triangle ABC where a trapezium BCPQ is drawn with BP=CQ=2 , PQ=1 and AP+AQ=sqrt7 . Note: there are 2 possible interpretations.
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problemChord
Equal touching circles have centres on a line. From a point of this line on a circle, a tangent is drawn to the farthest circle. Find the lengths of chords where the line cuts the other circles.
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problemLittle and Large
A point moves around inside a rectangle. What are the least and the greatest values of the sum of the squares of the distances from the vertices?
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problemSquare Pair Circles
Investigate the number of points with integer coordinates on circles with centres at the origin for which the square of the radius is a power of 5.
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problemThe Dodecahedron
What are the shortest distances between the centres of opposite faces of a regular solid dodecahedron on the surface and through the middle of the dodecahedron?
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problemPythagoras Mod 5
Prove that for every right angled triangle which has sides with integer lengths: (1) the area of the triangle is even and (2) the length of one of the sides is divisible by 5.
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articleIncircles Explained
This article is about triangles in which the lengths of the sides and the radii of the inscribed circles are all whole numbers. -
articleAll Is Number
Read all about Pythagoras' mathematical discoveries in this article written for students.