## Using Pi to Find the Area and Circumference of a Circle

3/18/2013

You may have learned this topic in elementary. In case you have forgot, here is a blog post to refresh your memory! Lets say that there is a circle with a radius of 3 ft. To find the area, you would simply multiply Pi by R^2. So in this case, it would be 3.14 times 9. I got the 9 from the squaring 3. The area of the circle would be 28.26 ft. That wasn't too difficult, right? Now how do you find the circumference of a circle? That isn't difficult either!
You can find out the circumference from using two measurements, the radius or the diameter. The diameter would be easier to use because it takes a fewer steps and it gets you the same answer if you use the radius. The formula for finding the circumference is c=3.14xD. In this case, the diameter would be 6 feet. Plug in the numbers then times by Pi. The formula for the radius is c=2x3.14xR. Plug in the numbers and use the formula.

3/11/2013

This blog will be all about Pi. I'm not talking about the pie that we eat for dessert, but the pi that is used in many problems in math! Pi is a number that has like 50 numbers in it; I think it goes on forever! The first 3 numbers of it is 3.14. That are all the numbers that I know in Pi. As a fraction, Pi is 22/7. I don't think I have used Pi in 7th grade pre-algebra yet, but I do remember using some of it in 6th grade. I remember that we used Pi to find the diameter and radius of a circle. That's all I could really think of right now when it comes to using Pi.
Why is Pi special, and what's so awesome about it? Well, if you're a math lover, I think you would know all about Pi, but for me, I don't. I think Pi is special and it's been used for a while now because it helps us solve certain problems, such as the one I stated in the 1st paragraph. I'm not certain of this, but I also think that Pi is the circumference of a circl

## Graphing a Line

3/4/2013

Did you know that you could graph a line based on a formula (y=m(x)+b)? The "m" in the equation is the slope, the "x" is the integer, and the "b" is the y-intercept. Take y=5x-3 as an example.  If the y intercept is negative, instead of the addition sign, it will be a subtraction sign. So now that we know the equation, how do we graph a line? Well, that is pretty easy to figure out.
First, you have to find the y-intercept. In this case, the y-intercept is -3. I know this because it is in the formula. Once you know that, then you could start graphing the line. You would start at -3, then go up 5 units. If the 5 was negative, you would go down 5 units. When you get to the location, you move 1 unit to the right. That's how you graph a line based on the equation. It's not that difficult to understand once you know the formula.