Please help! Geometry Circles?

2 Answers
Feb 27, 2018

The shaded area = 1085.420262mm^2

Explanation:

the area for the big half circle:
Half the Area = (pi r^2)/2
so
(pi 29^2)/2 = 1321.039711 mm^2

small circle area:
Area = pi r^2
pi 5^2 = 78.53981634 mm^2

now the shaded area will be:
1321.039711 - (78.53981634 * 3) = 1085.420262mm^2

  • times 3 because you have three white small circles

if I'm wrong someone corrects me, please
thanks :)

Feb 27, 2018

A=345.5pi

Explanation:

Area of a circle is:

pir^2

The area of a semicircle is:

1/2pir^2

The radius in respect to diameter is:

d/2

The area of the shaded region is the area of the semicircle minus the area of the three white circles.

The area of the semicircle we have here is:

A=1/2pi(58/2)^2

A=1/2pi(29)^2

A=1/2pi841

A=420.5pi

The area of three white circles is:

A=3*pi*5^2

A=3*pi*25

A=75*pi

The area of the shaded region is:

A=420.5pi-75pi

A=345.5pi