When you go to a pizza restaurant, I don't suppose you are wondering where the maths is, do you?
Maybe you do. I am usually too hungry!
Take this humble pizza, where is the maths in that?
The slice you have just cut for yourself (looks a little small to me) is called a sector.
A sector is an area between an arc of a circle at its two radii.
Now to find out how much you have cut you need to find the area of the sector.
As ever there is a formula to do this.
As we are looking a part of a circle is involved of course.
To find the area of a circle we use the formula Πr² or (π x r x r)
It makes sense to use this to find the sector.
Remember you can use the π button on your calculator or use the value 3.14
Area of a sector = angle/360 x π x radius x radius (angle/360 x πr²)
Let's calculate how hungry you are!
The radius of the pizza is 6 cm and the angle is 50°
50 ÷ 360 x π x 6 x 6 = 15.71 cm²
To save a lot of writing down in mid calculation, it is best if you use a scientific calculator as you can put the whole formula in at once.
The calculator is clever enough to know the value of pi too.