You discovered Pi yesterday. If each object was measured with 100% accuracy, the ratios of circumference to diameter would have all been exactly the same.
Pi is a weird number because its decimals go on forever without ever repeating. There are computers working around the clock to try and find an end to it. Check this out:
When using pi in class work we can get away with using 3.14. But when you graduate to building spaceships, where being off by a hair in a measurement can cause a shuttle to burn up on re-entry, the accuracy of keeping all of the decimals in pi can save lives.
There is pi button on your calculator, it will help you in your calculations. Find it now!
Study the videos and pictures below:
Area is the amount of space there is on a flat surface. The size of a house (square feet), a piece of land (acres), wrapping a present (how much paper do you use?); These are all times when we need to calculate area.
When we calculate areas of shapes with straight lines, we can use formulas that will help us score the answer efficiently:
When we are looking to find the area of a curved surface it gets a little tricky. Use the gridlines to estimate the circles below, try a find a relationship between 3.14, radius and the area of a circle.
BIG DEAL HERE:
Look at your estimates of the area and try and find how the radius and 3.14 (∏) could be factors in this equation.