Three congruent circles of radius 6 inches are mutually tangent to one another. Compute the area enclosed between them.

Individual problems from throughout mathematics history, as well as articles that include problem sets for students.

Discussion of 15th century French manuscript, with translation of its problems, including one with negative solutions

Curve sketching, tangent lines, and optimization, explored via interactive applets

Determine the radii of three equal circles decribed within and tangent to a given circle, and also tangent to each other

The radius of a circle is 3.20 meters. Compute to within .001m the areas of the inscribed and circumscribed equilateral triangles.

A vessel is anchored in 3 fathoms of water and the cable passes over a sheave in the bowspirt which is 6 ft above the water.

Wanting to know the breadth of a river, I measured a base of 500 yards in a straight line close by one side of it.

If in a circle ABDC, circumscribe an equilateral triangle ABC; the straight line AD is equal to the sum of the two straight lines BD and DC: required a demonstration.

A cat sitting on a wall 4 cubits high saw a rat prowling 8 cubits from the foot of the wall;

A castle has n rooms each of which has 7 samurai in it.