Question

Hi!

Answer 1

9514 1404 393

Answer:

  1. area DEF = 2π cm²

  2. arc JK = 2π cm

Step-by-step explanation:

1. The area is given by ...

  A = 1/2r²θ . . . . . where r is the radius and θ is the central angle in radians

Your sector has an area of ...

  A = (1/2)(3 cm)²(80(π/180)) = (1/2)(9 cm²)(4/9π)

  A = 2π cm²

__

2. The length of an arc is ...

  s = rθ . . . . . . . where r is the radius and θ is the central angle in radians

  s = (5 cm)(72(π/180)) = (5 cm)(2/5π)

  s = 2π cm . . . arc length

_____

Additional comment

There are π radians in 180°, so an angle in degrees can be converted to an angle in radians by multiplying by π/180°. (The units of degrees cancel, leaving a pure number. "Radians" have no units.)