find the radius of the circle whose sector area is 426 sq.cm. and central angle 24

a = 1/2 r^2 θ, so

1/2 r^2 * π/15 = 426

oops. That's 2π/15

To find the radius of the circle whose sector area is 426 sq.cm. and central angle 24 degrees, you can use the following formula:

Sector Area = (pi * r^2 * theta) / 360

Where:
- Sector Area is the given area of the sector (426 sq.cm. in this case)
- r is the radius of the circle (what we want to find)
- theta is the central angle of the sector (24 degrees in this case)
- pi is a mathematical constant approximately equal to 3.14159

Let's rearrange the formula to solve for r:

r^2 = (Sector Area * 360) / (pi * theta)

r = sqrt((Sector Area * 360) / (pi * theta))

Now we can substitute the given values into the formula:

r = sqrt((426 * 360) / (3.14159 * 24))

Calculating the expression inside the square root gives:

r = sqrt(153360 / 75.398)

r = sqrt(2037.893)

So, the radius of the circle is approximately 45.13 cm.