501 Geometry Questions

Rhombuses

The area for rhombuses is completely different from the other formulas
presented so far. The formula for the area of a rhombus is the product of
its two distinct diagonals.

Area of a Rhombus = ^12 (diagonal 1 )(diagonal 2 )

or A=^12 (d 1 )(d 2 )

Regular Polygons

Remember that a regular polygon has all equal sides and all equal angles. All
regular polygons contain apothems. An apothem is a line segment drawn at
a right angle from the midpoint of any side to the center of the polygon. All
apothems are perpendicular bisectors. The formula for the area of a regu-
lar polygon is one-half of the apothem times the perimeter of the polygon.
(Remember that the perimeter of regular polygons is ns, where nis the num-
ber of sides, and sis the side length.)

Area of a Regular Polygon = ^12 (apothem)(perimeter),

orA = ^12  (a)(n)(s)

Apothem

diagonal 1

diagonal 2

501 Geometry Questions