Answer:

1. D= 10 -> r=5

A= (pi r^2)/2

A= (3.14*5^2)/2

A= (3.14*25)/2

A= (78.5)/2

A= 39.25 *2 (*2 because 2 semicircle)

A= 78.5 cm^2

2. Given- Diam= 15 r= 7.5

A= h*b/2

A= 15*7.5/2

A= 112.5/2

A= 56.25 ft.^2

3.  Given- S=9cm

A=S^2

A= 9^2

A= 81cm^2

Step-by-step explanation:

[^x= exponent]

1. The diameter of the circle 10 cm because the center is place at the width of the rectangle.

Then we just subtitute the given then solve

2. The base is 15 ft. because its at center and the the diameter is 15 ft.

The radius 7.5 because [r= Diameter/2]

Height = Radius because again the base is at the center so we can conclude that the radius is the height.

Then we just subtitute the given and solve.

3. Its simple because the valu of the side is given.

So, its just 9^2.