Area : The amount of unit squares that is needed to cover a 2-dimensional shape.

Centimeter : A centimeter ($cm$) is $\frac{1}{100}$ of a meter.

Half : A Half is the number equal to $\frac{1}{2}=0.5.$

Length : Length is the attribute of a one-dimensional shape that can be measured with a measuring tape.

Product : A product is the result of a multiplication.

Right angle : A right angle is an angle equal to $90^{\circ}.$

Right triangle : A right triangle is a triangle that has a right angle. The sides that form the right angle are called legs, the third side is called hypotenuse. The area of a right triangle is half the product of the lengths of the two legs. The Pythagorean theorem is an important theorem for right triangles that allows to calculate the third side of a right triangle given the other two.

Square centimeter : Square centimeter or $cm^2$ is a unit of measurement for measuring area. 1 square centimeter is the area of a square with side length 1 $cm,$ so 10,000 $cm^2$ are one $m^2.$

Addition : Addition is the mathematical operation that describes increasing a number by an amount equal to a second number. The mathematical symbol for addition is the plus sign $+.$ The term addition is also used for a generalization of this basic operation on numbers to functions, vectors and matrices.

Alternate exterior angle : When two parallel lines are crossed by a third line, alternate exterior angles are a pair of angles that are not between the two parallel lines and are on opposites sides of the crossing line. Alternate exterior angles are equal.

Alternate interior angle : When two parallel lines are crossed by a third line, alternate interior angles are a pair of angles that are between the two parallel lines and are on opposites sides of the crossing line. Alternate interior angles are equal.

Exterior angle : When looking at two parallel lines cut by a third line, exterior angles refer to angles that are not between the two parallel lines. In a polygon an exterior angle refers to the angle at a corner that lies outside the polygon.

Line : A line AB is a one-dimensional shape that includes the points A and B, all the points on the line segment in between A and B and all the points of the straight extension of the line segment beyond A and B. A line does not have an endpoint.

Parallel : Two lines in a two-dimensional plane are called parallel if they never cross.

Straight angle : A straight angle is an angle equal to $180^{\circ}.$

Third : A third either refers to the third object in an ordering or to the number $\frac{1}{3}=0.\overline{3}.$

Coordinate : A coordinate is a number that describes the location of a point in space with respect to a direction.

Coordinate system : A coordinate system is a system to describe and visualize points in space (most commonly a two-dimensional or three-dimensional space). Every point is described by a number of coordinates equal to the dimension of the space.

Counterclockwise : Counterclockwise specifies a direction of a rotation in the opposite direction of the direction in which the hands of a clock are moving.

Degree : For angles one degree is defined as the angle represented by a $\frac{1}{360}$ of the angle represented by a full circle. For measuring temperatures one can use either degrees Celsius or degrees Fahrenheit. In a polynomial the degree describes the highest exponent of $x$ that has a non-zero coefficient. For example the degree of $1+x+x^2$ is 2.

Map : In mathematics mapping means assigning exactly one value to an object. A function maps every $x$ to exactly one $y.$

Point : A point is an element in a space. Shapes are made of sets of points.

Rotation : A rotation is a transformation that turns a shape around. A rotation turns shapes into congruent shapes.