Perpendicular Bisectors and Circumcircle
? Video Tutorial Perpendicular Bisector: Intersects a line segment at a right angle and divides it into two equal parts, ensuring each point on the bisector is equidistant from both endpoints. Constructing the Perpendicular Bisector: 1) Use a ruler to locate the midpoint, then draw a perpendicular line through it. 2) Use a compass to […]
Angle Bisectors and Incircle
? Video Tutorial Angle Bisector: A line or ray that divides an angle into two equal parts. For example, if the angle is $60^circ$, the angle bisector will split it into two angles of $30^circ$ each. Constructing Bisectors with a Compass: Draw an arc from the vertex to create intersection points. Then, without changing the […]
Solids and Units of Volume
? Video Tutorial Solids: 3D shapes with length, width, and height, like cuboids and cubes. They have faces (flat surfaces), edges (where faces meet), and vertices (where edges meet). Volume and Unit Cubes: Volume measures the space a solid occupies, typically in cubic units. A cubic centimetre ($text{cm}^3$) is the volume of a cube with […]
Polygons and Types of Quadrilaterals
? Video Tutorial Definition of Polygons: A polygon is a two-dimensional, closed shape made only of straight line segments, with no gaps or curved edges. Naming Polygons by Sides: Triangles (3 sides), quadrilaterals (4 sides), and pentagons (5 sides) etc. Sum of Interior Angles: The sum of a polygon’s interior angles is given by the […]
Circles and Their Properties
? Video Tutorial Basic Circle Properties: A circle is defined by all points equidistant from its centre. This constant distance from the centre to any point on the circle is called the radius. Circle Measurements: The diameter is twice the radius. A chord is any line segment connecting two points on the circle, with the […]
Measurement and Types of Angles
? Video Tutorial Types of Angles: Angles are classified by size — acute ($<$ 90°), right (90°), obtuse (90° $<$ ? $<$ 180°), straight (180°), reflex (180° $<$ ? $<$ 360°), and full angle (360°). Measuring Angles with a Protractor: Align the protractor’s centre with the vertex and the zero line with one arm. Read where the other arm crosses […]
Angle Relationships in Intersecting and Parallel Lines
? Video Tutorial Vertically Opposite Angles: When two lines intersect, they form two pairs of opposite angles. Vertically opposite angles are always equal. Adjacent Angles: When two angles are adjacent and form a straight line, they add up to 180°. This makes them supplementary angles. Parallel Lines and Transversals: When a transversal intersects parallel lines, […]