Nicala's Blog

in chapter seven section two
all you have to do is remember the formulas and the hints to pass this section

formulas
s=r(theta)
k-one half(r)squaredtheta
k=onehalf (r)(s)

s=arc length
r=radius
theta=central angle
k=area

word problem hints

theta=apparent size
s=diameter
r=distance between objects

Also your theta must be in radians

Example

A sector of a circle has an arc length of 8 cm and the area of 75 cm. Find its radius and the measure of its central angle.

s=8cm
k=75 cm
r=?
theta=?

using one of the formulas for area
k=one half(r)(s)

75=(1/2)(r)(8)
75=4r
then you divide four by both sides
r=18.75cm

next you use the arclength formula
s=(r)theta
8=(18.75)(theta)
theta=2.34375 rads