Geometrical Structures Vocabulary

Point: This is defined as a specific location within a given space.
Line: This is the resulting product of a single point moving continuously along a specific path.
Straight Line: This represents the shortest possible distance existing between any $2$ points.
Horizontal Line: A line that is specifically drawn from a leftward to a rightward direction.
Vertical Line: A line specifically drawn from the top-most point to the bottom-most point.
Inclined Line: This refers to a line that is oriented diagonally.
Perpendicular Lines: These are lines that intersect or meet to form exact $90^{\circ}$ angles with one another.
Parallel Lines: These are lines positioned side by side that will never intersect or meet, regardless of how far they are extended in either direction.
Curve Line: This refers to any line that is not straight in its trajectory.
Arc: This is a connected section taken from the total circumference of a circle.
Circle: A closed geometric figure that is bounded by exactly one curved line.
Angle: This geometric figure is formed whenever two lines intersect or meet.
Straight Angle: An angle that measures exactly $180^{\circ}$ .
Right Angle: An angle that measures exactly $90^{\circ}$ .
Acute Angle: An angle whose measure is strictly less than $90^{\circ}$ .
Obtuse Angle: An angle whose measure is strictly greater than $90^{\circ}$ .

Circles: A circle is defined as the complete set of all points in a plane that are located at a specific, given distance from a fixed point known as the center.
Diameter: A straight line that passes directly through the center of the circle, connecting two points on the boundary.
Radius: This is a line segment extending from the center of the circle to any point located on the circle's boundary.
Chord: A line segment where both endpoints lie on the boundary of the circle.
Segment: A specific portion of a circle that is bounded by a combination of an arc and a chord.
Tangent: A straight line that intersects the boundary of a circle at exactly one ( $1$ ) point.
Secant: A straight line that passes through two ( $2$ ) points on the circle's boundary but does not pass through the center.
Quadrant: A specific part of a circle bounded by two radii forming a $90^{\circ}$ angle; it constitutes exactly $\frac{1}{4}$ of the total circle.
Sector: A part of a circle that is bounded by two radii and a connecting arc.
Concentric Circles: These are two or more circles that share a common center point.
Eccentric Circles: These are circles located inside another circle that possess different center points.

Triangle: A polygon defined by having three ( $3$ ) sides and three ( $3$ ) angles.
Equilateral Triangle: A triangle where all three sides are equal in length.
Isosceles Triangle: A triangle where exactly two ( $2$ ) sides are equal in length.
Right Triangle: A triangle that contains one angle measuring exactly $90^{\circ}$ .
Scalene Triangle: A triangle in which no sides are equal and no angles are equal.

Quadrilateral: A polygon defined by having four ( $4$ ) sides and four ( $4$ ) angles.
Parallelogram: A quadrilateral featuring two distinct pairs of parallel sides.
Square: A quadrilateral with four ( $4$ ) equal sides and four angles that each measure $90^{\circ}$ .
Rectangle: A quadrilateral with two unequal pairs of parallel lines and four angles that each measure $90^{\circ}$ .
Rhombus: A quadrilateral with four ( $4$ ) equal sides where the internal angles do not measure $90^{\circ}$ .
Rhomboid: A type of parallelogram where the internal angles do not measure $90^{\circ}$ .
Trapezoid: A quadrilateral featuring exactly one pair of unequal parallel lines and internal angles that do not measure $90^{\circ}$ .
Trapezium: A quadrilateral with unequal sides and no parallel lines.