About this topic
Before you begin
Choose triangle heights, calculate cuboid and liquid volumes, and use triangle and right-angle properties in composite figures.
Learning goals
- Identify a triangle's base and perpendicular height
- Calculate the area of a triangle
- Calculate the area of a composite plane figure
- Calculate the exposed boundary of a composite plane figure
- Calculate the volume of a cube or cuboid
- Calculate the volume of liquid in a rectangular tank
- Relate cubic centimetres to millilitres and litres
- Connect triangle, rectangle and square facts to deduce angles in a drawn composite figure
- Apply the sum of the three interior triangle angles
- Deduce every missing angle from the equal sides of an isosceles triangle
- Deduce all three angles from an equilateral triangle
- Deduce missing angles in a right-angled triangle
- Use the guaranteed side and angle properties of an isosceles triangle
- Use the guaranteed side and angle properties of an equilateral triangle
- Use perpendicular sides and complementary angles of a right-angled triangle
- Use right corners and angle partitions between connected rectangles or squares
Syllabus statements covered
- Concepts of base and height of a triangle
- Area of triangle
- Finding the area and perimeter of composite figures made up of squares, rectangles and triangles
- Volume of a cube/cuboid
- Finding the volume of liquid in a rectangular tank excluding conversion between cm³ and m³
- Relationship between ℓ (or ml) with cm³
- Properties of
- Isosceles triangle
- Equilateral triangle
- Right-angled triangle
- Angle sum of a triangle
- Finding unknown angles, without additional construction of lines, in composite geometric figures involving
- Square
- Rectangle
- Triangle
Choose a lesson
Work through them in order.
- Not startedTriangle base, height and areaNextFind a perpendicular height and connect triangle area with half a parallelogram.
- Not startedCuboids and liquid volumeNextUse complete layers to derive cuboid volume and measure liquid in a rectangular tank.
- Not startedTriangle angle propertiesNextUse the angle sum and equal-side markings to justify unknown triangle angles.
- Not startedAngles between rectangles and squaresNextUse right corners and distinguish separate gaps from overlapping corner parts.