An altitude of a triangle is a line segment connecting a vertex to the line containing the opposite side and perpendicular to that side.
What is an altitude?
100
A circle is the set of all points in a plane that are equidistant from a given point in the plane, which is the center of the circle.
What is a Circe?
100
A convex polygon is any polygon that is not concave.
What is concave polygon?
100
A line has only one dimension: length. It continues forever in two directions (so it has infinite length), but it has no width at all. A line connects two points via the shortest path, and then continues on in both directions.
What is line?
100
A median is a segment connecting any vertex of a triangle to the midpoint of the opposite side.
What is a median?
200
The angle-angle-angle (AAA) similarity test says that if two triangles have corresponding angles that are congruent, then the triangles are similar. Because the sum of the angles in a triangle must be 180°, we really only need to know that two pairs of corresponding angles are congruent to know the triangles are similar.
What is AAA?
200
The circumcenter of a triangle is the point where the three perpendicular bisectors meet. This point is the same distance from each of the three vertices of the triangles.
What is circumcenter ?
200
If angle A is an acute angle in a right triangle, the cosine of A is the length of the side adjacent to angle A, divided by the length of the hypotenuse of the triangle. We often abbreviate this as cos A = (adjacent)/(hypotenuse).
What is cosine ?
200
A line segment is the portion of a line lying strictly between two points. It has a finite length and no width.
What is line segment ?
200
A midline is a segment connecting two consecutive midpoints of a triangle.
What is midline?
300
An angle bisector is a ray that cuts the angle exactly in half, making two equal angles.
What is angle Bisector?
300
A concave polygon is any polygon with an angle measuring more than 180°. Concave polygons look like they are collapsed or have one or more angles dented in.
What is concave Polygon ?
300
A cross section is the face you get when you make one slice through an object.
What is cross section?
300
A vector can be used to describe a translation. It is drawn as an arrow. The arrowhead points in the direction of the translation, and the length of the vector tells you the length of the translation.
What is a Vector?
400
A central angle is an angle with its vertex at the center of a circle.
What is central angle?
400
When three or more lines meet at a single point, they are said to be concurrent. In a triangle, the three medians, three perpendicular bisectors, three angle bisectors, and three altitudes are each concurrent.
What is concurrent?
400
An edge is a line segment where two faces intersect.
What is edge?
400
A polygon has line symmetry, or reflection symmetry, if you can fold it in half along a line so that the two halves match exactly. The folding line is called the line of symmetry.
What is a line symmetry?
400
A Venn diagram uses circles to represent relationships among sets of objects
What are Venn Diagrams?
500
The centroid of a triangle is the point where the three medians meet. This point is the center of mass for the triangle. If you cut a triangle out of a piece of paper and put your pencil point at the centroid, you could balance the triangle.
What is Centroid of a triangle?
500
Congruent triangles are triangles that have the same size and shape. In particular, corresponding angles have the same measure, and corresponding sides have the same length.
What are congruent triangles?
500
A face is a polygon by which a solid object is bound. For example, a cube has six faces. Each face is a square.
What is face?
500
A point specifies only location; it has no length, width, or depth. We usually represent a point with a dot on paper, but the dot we make has some dimension, while a true point has dimension 0
What is a point?
500
A vertex is the point where two sides of a polygon meet.