GEOMETRY VOCABULARY AND DEFINITIONS:
Perimeter-distance around a figure
Area of a rectangle= b x h
Area of a triangle= 1/2 (b x h)
Angles: Acute, Straight, Obtuse, Right
Rotation-Clockwise or counterclockwise
Triangles: Equilateral (3 congruent sides), Isosceles (2 congruent sides), Scalene (no congruent sides)
Circumference-distance around a circular object
Diameter-a chord that passes through the center of a circle is a diameter.
Radius-a line segment with one endpoint at the center of a circle and the other endpoint on the circle
Circumference= 3.14 x diameter
Conversions: see below (Measurements)
SALAD-Small to Large, Divide ie.) 24 inches (24 divided by 12) =2 ft.
LONESOME -Large to Small, Multiply ie.) 3 yards (3 x 3) = 9 ft.
triangle "tri" means 3
quadrilateral "quad" means 4
pentagon "pent" means 5
hexagon "hex" means 6
octagon "oct" means 8
decagon "deca" means10
polygon "poly" means many
SIMILAR-Two figures are similar if they have the same shape. They do not have to be the same size.
CONGRUENT-Two figures are congruent if their corresponding sides and angles are equal.
TESSELATION-covers a surface with no gaps or overlaps
PRISM-is a solid figure that has 2 congruent faces called bases. A prism is named by the polygons that form its bases. example: hexagonal prism-faces are rectangles, bases are hexagons
Pyramid is a solid figure with one base that is a polygon and three or more faces that are triangles with a common vertex. A pyramid is named by the polygon that forms its base. example: hexagonal pyramid (faces are triangles, base is a hexagon)