Question

I need to find the arc of GFE, next, I need to find the circumference AND area with a radius of 5 mm. Then the final questions ask to Write the equation of a circle with a center at (-1,2) and a diameter of 12.
I will be very thankful for your help, this is a required assignment of mine and I have been struggling to get it done. Thank you :)

Answer 1

Arc GHE is 40 + 80 or 120 so arc GFE is 360 (total measurement in a circle) - 120 which is 240. The circumference of a circle is 2*pi*r so in this case it will be 2*pi*5 or 10pi (you can also write it as approximately 31.4). The area of a circle is pi*r² so it'll be pi*5² or 25pi (you can write it as approximately 78.5 also). The equation of a circle is (x-h)² + (y-k)² = r² where (h,k) is the center of the circle and r is the radius. Input your values. The equation of this circle is (x+1)² + (y-2)² = 6² (The radis is 6 because the diameter is 12)

I hope this helps!

Answer 2

A full circle is 360 degrees.

You are given the angles for GH, HE and FE, subtract those from 360 to find the angle for FG:

360 - 110 - 80 - 40 = 130 degrees.

Now for the arc GFE add FG and FE:

Arc GFE = 130 + 110 = 240 degrees.

Circumference = 2 x PI x r

Using 3.14 for PI:

Circumference  = 2 x 3.14 x 5 = 31.4 mm or 10PI

Area = PI x r^2 = 3.14 x 25 = 78.5 mm^2 or 25PI mm^2

Equation of a circle with center at (-1,2) and diameter of 12:

The equation is written as (x-x1)^2 + (y-y1)^2 = r^2

x1 and y1 are the values of the center (-1,2) and r is the radius, which would be half the diameter.

The equation is: (x+1)^2 + (y-2)^2 = 36