Studied by 4 people
Point
A location in space with no dimensions.
Line
A one-dimensional figure extending infinitely in both directions.
Line Segment
A part of a line with two endpoints.
Ray
A part of a line that starts at a point and extends infinitely in one direction.
Plane
A flat, two-dimensional surface extending infinitely.
Collinear Points
Points that lie on the same line.
Coplanar Points
Points that lie in the same plane.
Acute Angle
Less than 90°.
Right Angle
Exactly 90°.
Obtuse Angle
Greater than 90° and less than 180°.
Straight Angle
Exactly 180°.
Reflex Angle
Greater than 180° and less than 360°.
Complementary Angles
Two angles whose sum is 90°.
Supplementary Angles
Two angles whose sum is 180°.
Vertically Opposite Angles
Angles opposite each other when two lines intersect, always equal.
Sum of Interior Angles
The sum of interior angles in a triangle is 180°.
Pythagorean Theorem
In a right-angled triangle, a² + b² = c², where c is the hypotenuse.
Congruent Triangles
Triangles with equal corresponding sides and angles.
Similar Triangles
Triangles with equal corresponding angles and proportional sides.
Isosceles Triangle
A triangle with at least two equal sides.
Equilateral Triangle
A triangle with all sides and angles equal.
Scalene Triangle
A triangle with all sides of different lengths.
Quadrilateral
A polygon with four sides.
Parallelogram
A quadrilateral with opposite sides that are equal and parallel.
Rectangle
A parallelogram with all angles equal to 90°.
Rhombus
A parallelogram with all sides equal.
Square
A rectangle with all sides equal.
Trapezium
A quadrilateral with one pair of parallel sides.
Kite
A quadrilateral with two pairs of adjacent sides equal.
Circumference
The distance around a circle.
Area of a Circle
The space contained within a circle, calculated as A = πr².
Chord
A line segment with both endpoints on the circle.
Arc
A portion of the circumference of a circle.
Sector
A region enclosed by two radii and an arc.
Tangent Properties
A tangent to a circle is perpendicular to the radius at the point of contact.
Sine Rule
For any triangle, a/sin(A) = b/sin(B) = c/sin(C).
Cosine Rule
For any triangle, c² = a² + b² - 2ab*cos(C).
