OTHER POLYGONS
87 . The 30-60-90 Triangle
The sides of a 30-60-90 triangle are in a ratio of You don’t need the Pythagorean
theorem.
If the hypotenuse is 6, then the shorter leg is half that, or 3, and then the longer leg is equal to
the short leg times or
88 . The 45-45-90 Triangle
The sides of a 45-45-90 triangle are in a ratio of
If one leg has a length of 3, then the other leg also has a length of 3, and the hypotenuse is
equal to a leg times or
89 . Characteristics of a Rectangle
A rectangle is a four-sided figure with four right angles. Opposite sides are equal. Diagonals
are equal.
Quadrilateral ABCD above is shown to have three right angles. The fourth angle therefore also
measures 90 degrees, and ABCD is a rectangle. The perimeter of a rectangle is equal to the sum
