click below
click below
Normal Size Small Size show me how
geometry of 2D
Geometry of 2D shapes
Term | Definition |
---|---|
Area | The number of square units needed to cover a given surface |
Trapezoid | A quadrilateral with exactly one pair of parallel sides |
Perimeter | The distance around a polygon |
Circumference | The distance around a circle |
Surface Area | The sum of the areas of the faces or surfaces of a three-dimensional figure |
Prism | A polyhedron that has two congruent polygon shaped bases and other faces that are parallelograms |
Volume | The number of cubic units needed to fill a given space |
Parallelogram | A quadrilateral with two pairs of parallel sides |
Diameter | A line segment that passes through the center of a circle and has end-points on the circle or the length of that segment |
Radius | A line segment with one end-point at the center of a circle and the other end-point on the circle or that length of the segment |
area of a rectangle | length x width |
area of a parallelogram | base x height |
area of a trapezium | ((a +b) x h)/2 |
area of a circle | 3.142 x radius x radius |
Area of a triangle | A = (b x h) divided by 2 |
Circumference of circle | Pi x d |
Perimeter of a rectangle (and parallelograms) | A = 2(L x W) |
Triangle Area = | 1/2 x base x perpendicular height |
Square Area = | base x base |
Rectangle Area = | base x height |
Parallelogram Area = | base x perpendicular height |
Trapezium Area = | 1/2 x height x (top + bottom) |
Circle Area = | π x r squared |
Area (rhombus) | bxh |
Acute Triangle | A triangle with 3 acute angles |
Right Triangle | A triangle that has a 90 degree angle (right angle) |
Obtuse Triangle | A triangle with one angle that is greater than 90 degrees. |
Square | Four equal sides and four right angles |
Rhombus | A parallelogram with four equal sides |
Trapezoid(US)/Trapezium(UK) | A quadrilateral with exactly one pair of parallel sides |
Pentagon | 5 sided polygon |
Octagon | 8-sided polygon |
Nonagon | 9 sided polygon |
Decagon | 10 sided polygon |
Heptagon | 7 sided polygon |
Hexagon | 6 sided polygon |