| Definition | Term | Letter | % Correct |
|---|---|---|---|
| For a triangle, it's one-half base times height; for a square it is a side squared | Area | A | 94%
|
| A line segment that goes from one point on a circle to another, through its center | Diameter | D | 89%
|
| A figure with nine sides and nine internal angles | Nonagon | N | 83%
|
| Term for any angle between 90 and 180 degrees | Obtuse | O | 81%
|
| The longest side, which is opposite the 90° angle, in a right triangle | Hypotenuse | H | 78%
|
| The corner point of a polygon or where the two segments of an angle meet | Vertex | V | 75%
|
| A triangle that has (at least) two equal or congruent sides | Isosceles | I | 72%
|
| The distance around a plane figure or the sum of all of the sides of a polygon | Perimeter | P | 72%
|
| A quadrilateral with four equal sides and perpendicular diagonals | Rhombus | R | 72%
|
| One of 4 regions on the Cartesian plane as determined by the axes | Quadrant | Q | 69%
|
| A quadrilateral in which a pair of opposite sides are parallel to each other | Trapezoid | T | 61%
|
| Line or segment which splits another segment or angle into two equal parts | Bisector | B | 58%
|
| A pair of angles that together add up to 90 degrees | Complementary | C | 58%
|
| A pair of angles that together add up to 180 degrees | Supplementary | S | 56%
|
| A quadrilateral with two sets of congruent, adjacent sides | Kite | K | 47%
|
| A self-similar figure, such as the Mandelbrot set | Fractal | F | 36%
|
| Line segment connecting a vertex of a triangle with the midpoint of the opposite side | Median | M | 36%
|
| An angle of a polygon created by extending one of the sides | Exterior angle | E | 33%
|
| A set of all points that have the same positional constraint | Locus | L | 22%
|
| An arc or full circle on a sphere that shares its center with a sphere | Great Circle | G | 8%
|