Ascientist enlarged a circular portion of a microscope slide to make it easier to count the number of bacteria present in the sample. he divided the circle into 5 sectors as shown below and plans to count bacteria only in the shaded sector. what is the area of the shaded sector to the nearest tenth of a square centimeter a.141.4 b.212.1 c.377.0 d.424.1

Option B.

Step-by-step explanation:

step 1

Find the central angle of the shaded sector

Remember that the diameter divide the circle into two equal parts ( 180 degrees each part)

so

Let

x -----> the measure of the central angle of the shaded sector

∠x+72°=180°

∠x=180°-72°=108°

step 2

Find the area of the circle

The area of the circle is

we have

assume

substitute

step 3

Find the area of the shaded sector

Remember that the area of the complete circle subtends a central angle of 360 degrees

so

by proportion find the area of a sector by a central angle of 108 degrees

quit

step-by-step explanation: