106k views
5 votes
Can someone Plss help me with my homework I don’t know really understand on how to find the regular figure

Can someone Plss help me with my homework I don’t know really understand on how to-example-1
User Almulo
by
4.6k points

1 Answer

3 votes

2To find the area of each regular polygon, we have to use the following formula:


A=(P\cdot a)/(2)

Where P is the perimeter of the polygon and a is its apothem.

9. To find the area of this polygon, find its perimeter and its apothem.

To find its perimeter multiply the sidelength, 14cm, times the number of sides of the polygon:


P=14cm\cdot9=126cm

To find the apothem, we have to use the following formula:


a=(l)/(2tan\theta)

Where l is the sidelength and θ is half the central angle. Replace l for 14 and θ for 20:


a=(14cm)/(2tan20)=19.23cm

Replace for these values and find the area:


A=(126cm\cdot19.23cm)/(2)=1211.49cm^2

10. To find the perimeter of this polygon we have to find its side length:


l=2rsin\theta

Where r is the radius and θ is half the central angle:


\begin{gathered} l=2(6ft)sin36 \\ l=7.05ft \end{gathered}

Find the perimeter by multiplying this sidelength by 5:


P=7.05ft\cdot5=35.25ft

Find the apothem using the same formula as in the other polygon:


a=(7.05ft)/(2tan36)=4.85ft

Find the area using these values:


A=(35.25ft\cdot4.85ft)/(2)=85.48ft^2

User Andbeonetraveler
by
4.2k points