Bertrand Russell once wrote, “Mathematics possesses not only truth but
supreme beauty, a beauty cold and austere, like that of sculpture, sublimely
pure and capable of a stern perfection, such as only the greatest art can
Can this be the same Russell who, together with Alfred Whitehead,
authored the monumental Principia Mathematica, which can by no means
be regarded as a work of art, much less as sublimely beautiful? So what
are we to believe?
The smaller angle between the two rays issuing from a vertex and passing through the other two vertices is called an (interior) angle of the triangle. The angle adjacent to an interior angle is called an external angle of the triangle. An external angle is equal to the sum of the two interior angles to which it is not adjacent.
Lines and angles Triangles Isosceles and equilateral triangles Rectangles, squares, and parallelograms Circles Advanced circle problems Polygons Cubes and other rectangular solids Cylinders Coordinate signs and the four quadrants Defining a line on the coordinate plane Graphing a line on the coordinate plane Midpoint and distance formulas Coordinate geometry Summing it up
In this chapter, you’ll review the fundamentals involving plane geometry, starting with the following: • • • • • • Relationships among angles formed by intersecting lines Characteristics of any triangle Cha...