Can somebody please help me with these equations, i would really appreciate it?

Question

Please Help. I am stuck on these equations and I need help on them:

1. The Radius of a circle is 4 units. What is the EXACT area in square units?

2. A circle X has a raduis MX that is 2 inches. The central angle MXY measures 60 degrees. What is the length of the arc MY in inches?

3. A circle has the equation xsquared+(y-2)squared=49. What is its center?

4. A circle Q has a radius QC that is 10 cm. The central angle CQA measures 180 degrees. What is the area of the sector swept out by acr CA in square centimeters?

5. A circle X has a radius MX that is 7 inches. The central angle MXY measures 65 degrees. What is the length of the arc MY in inches?

Answer 1

Area of a circle formula

A = π r²

A = 3.141592654(4)²

A = 3.141592654(16)

A = 50.26548246 Units

- - - - - - - - - -s-

Answer 2

1) The area of a circle is π r^2, so the exact area is 16π square units. If you're hoping to get an exact decimal, you're sh*t out of luck, because π is an irrational number, as is 16π.

2) If the angle is 60 degrees, then this section is 60/360 = 1/6 of the circle. That must mean the arc is 1/6 of the total circumference. So find the circumference of the circle (2 π r) and divide by 6.

3) When a circle's equation is in the form of
(x - h)^2 + (y - k)^2 = r^2, then the center is at (h, k)

4) If the central angle is 180 degrees, then what you have is a semi-circle. So just find the area of the full circle and divide the result by 2.

5) Use the same technique as in #2

Answer 3

1) area = pi * r^2 = 16pi