Year 8 Length, Shape and Area Key Formula Flashcards
What is perimeter?
The total distance around the outside of a 2D shape, measured in mm/cm/m
For a circle, it is called the circumference.
What is circumference?
The distance around the edge of a circle (or any curvy shape)
It is a specific type of perimeter.
What is the area formula for a parallelogram?
Area = base x perpendicular height
Measured in m²/cm²/mm².
What is the area formula for a triangle?
Area = ½ x base x perpendicular height
Measured in m²/cm²/mm².
What is the area formula for a rectangle?
Area = base x height
Measured in m²/cm²/mm².
What is the area formula for a trapezium?
Area = ½(a + b) x height
Measured in m²/cm²/mm².
What is the formula for the circumference of a circle?
Circumference = 2πr or πd
Where r is the radius and d is the diameter.
What is the area formula for a circle?
Area = πr²
Where r is the radius.
What is volume?
A measure of how much space an object takes up, measured in m³/cm³/mm³
It quantifies three-dimensional space.
What is a prism?
A 3D solid object with two identical ends and flat sides
Examples include triangular prisms and rectangular prisms.
What is a cylinder?
A 3D solid object that has two flat ends which are circles and one curved side
Common examples include cans and pipes.
What is the volume formula for a prism?
Volume = area of cross section x length
The area of the cross-section is perpendicular to the length.
What is the volume formula for a cylinder?
Volume = πr²h
Where r is the radius and h is the height.
What is surface area?
The total area of all of the faces of a 3D object
Important for understanding the extent of an object’s exterior.
What is the surface area formula for a prism?
Surface area = total area of all of the faces
Each face can be calculated separately and summed.
What is the surface area formula for a cylinder?
Surface area = 2πr(h + r)
Where r is the radius and h is the height.
