Prove that the area of a regular polygon can be given by the product of its perimeter and half the radius of the inscribed circle.

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A portrait gallery of mathematicians, mostly taken from the collection at the Dibner Library of the Smithsonian, with permission.

Given a pyramid 300 cubits high, with a square base 500 cubits to a side, determine the distance from the center of any side to the apex.

An image of the calendar, together with instructions for its use

This is the title page to the 1811 edition of the Descriptive Geometry of Gaspard Monge (1746-1818). This book deals with methods for representing three-dimensional objects in two dimensions. It was written to accompany Monge's courses at the Ecole Polytechnique in Paris.

Having been given the perimeter and perpendicular of a right angled triangle, it is required to find the triangle.

Find two numbers, x and y, such that their sum is 10 and x/y + y/x = 25

If 40 oranges are worth 60 apples, and 75 apples are worth 7 dozen peaches, and 100 peaches are worth 1 box of grapes and three boxes of grapes are worth 40 pounds of pecans, how many peaches can be bought for 100 oranges?

The incircle O(r) of triangle ABC touches AB at D, BC at E and AC at F. Find r in terms of AD, BE and CF.

In how many ways can a vowel and a consonant be chosen out of the word "logarithms?"