LAST ASSIGNMENT

CIRCLE

The last meet with Dr. Marsigit as my lecture for English II, He give me task to explain to my friend about topic of mathematic. I choice circle, and my partner is Ambar Puspita who ever called Tata. I do it in my house at Saturday, January 10, 2009.

First I explain the definition of circle. A circle is a simple shape of Euclidean geometry consisting of those points in a plane which are the same distance from a given point called the center. The common distance of the points of a circle from its center is called its radius. A diameter is a line segment whose endpoints lie on the circle and which passes through the centre of the circle. The length of a diameter is twice the length of the radius. The ratio of a circle's circumference to its diameter is π (pi), a constant that takes the same value (approximately 3.1416) for all circles or use pi 22/ 7 for the radius that have factor of 7. Thus the length of the circumference is πd, or 2πr, where d is diameter and r is radius. And the area of circle is πr^2.

The area and circumference of circle earn symbol with

A = πr^2 or A = (πd^2)/ 4

C = πd or C = 2πr

With: A: area or circle r: radius pi: 22/ 7 or 3.14

C: circumference d: diameter (2r)

For the example : A circle with 7 in radius. How is the area of its?

Solution: A= πr^2 we use pi= 22/ 7 because the radius of circle is 7 have factor 1 and 7. So the area = (22/ 7 )*7*7 = (22*49)/ 7= 22*7( the denominator and numerator devided by 7)= 154

We get the solution, so the area of circle is 154.

Until here Tata understand what I explain to her just often she confuse with my pronunciation that not yet fluently. Then I give her an exercise, she did it easily because topic of circle is easy to understand and have learned at elementary school. With this task we learn English together because we explaining each other. She take cube to explained to me, she do it well. We like this task because we can explore our English in math and learn how to be teacher when explain some topic next.

Source:

http://en.wikipedia.org/wiki/Circle