Examples:

general pattern  See pattern.

genus  The number of holes in a geometric shape, used to classify shapes in topology; in general, a class or group.  Shapes with the same genus are topologically equivalent.  See also topology.

geometric solid  A 3-dimensional shape bounded by surfaces.  Common geometric solids include the rectangular prism, square pyramid, cylinder, cone, and sphere.  Despite it name, a geometric solid is “hollow;” it does not include the points in its interior.

Geometry Template  An Everyday Mathematics tool that includes a millimeter ruler, a ruler with sixteenth-inch intervals, a half-circle and a full-circle protractor, a percent circle, pattern-block shapes, and other geometric figures.  Tiny holes at selected inch and centimeter marks allow the template to serve as a compass.

girth  A measurement around a 3-dimensional object.

Golden Ratio  A ratio of approximately 1.618 to 1.

Golden Rectangle  A rectangle in which the ratio of the length of the longer side to the length of the shorter side is the Golden Ratio, or about 1.618 to 1.  The shape of a standard index card 5 inches by 3 inches is nearly a Golden Rectangle.

great span  The distance from the tip of the thumb to the tip of the fourth (little) finger, stretched as far as possible.

greatest common factor  The largest factor that two or more numbers have in common.  For example, the common factors of 24 and 36 are 1, 2, 3, 4, 6, and 12.  The greatest common factor of 24 and 36 is 12.

grouping symbols  Symbols such a parentheses ( ), brackets [ ], or braces { } that indicate the order in which operations in an expression are to be done – for example, (3 + 4) * [(8 + 2)/5].

handicap  In sports and games, points added to (or subtracted from) a player’s score in order to equalize the player’s chance of winning.  A handicap may be given to bowlers whose average score is less than 200.  Golfers use a formula based on past performance to calculate their handicap.

height of a parallelogram  See base of a parallelogram.

height of a rectangle  See base of a rectangle.

height of a 3-dimensional figure  See base of a 3-dimensional figure.

height of a triangle  See base of a triangle.

heptagon  A polygon with seven sides.

hertz  A unit of frequency.  1 hertz (Hz) is a frequency of 1 vibration per second.  A sound wave with a frequency of 150Hz vibrates 150 times per second.

hexagon  A polygon with six sides.

horizon (line)  Where the Earth and sky appear to meet forming a line.

horizontal  Positioned in a left-right orientation; parallel to the horizon line.

hypotenuse  In a right triangle, the side opposite the right angle.