2D Shapes and 3D Solids
Surface area of prisms
A prism is a solid woth the same cross-section throughout it's length.
A right prism is a prism where the cross-section is at right angles to the length of the solid.
The cross section can be any flat shape.
Volume of prisms
Volume of a prism = cross-sectional area + length
Capacity is the volume of liquid a 3D shape will hold.
Circumference of a circle
The circumference (C) is the perimeter of a circle. The center of a circle is marked by using a dot.
The radius (r) is the distance from the center to the circumference.
The diameter (d) is a line from one edge to another through the center.
An arc is part of the circumference.
π
π = 3.141592653...
To find the circumference of a circle, use the equation C = πd
Key:
Circumference = C Diameter = d
Radius = r
To find the area of a circle use the following formula:
A = π r squared
Area of a circle
The formula for the area of a circle is A=πr
Plural of radius is radii.
Cylinders
To find the surface area of a cylinder: 2 π r + 2 π r h
To find the volume of a cylinder: π r h
Pythagoras' theorem
The longest side eof a right-angle is called the hypotenuse.
Pythagoras' theorem shows the relationship between the length of threee sides of a right-angled triangle.