Question

I need help to solve it

Answer 1

Looking at your picture, you have 1 rectangles with 2 semicircles attached to the side.

The rectangle has dimensions of 8m by 10 m and the semicircle has a diameter of 10

now, the area of a rectangle is A=b*h
where A- area
b- base = 8m
h-height= 10m

the area of a circle is
$A=\pi r^2$
and a semicircle is just one half the area of a circle, so
$A_{semi}= \frac{1}{2} \pi r^2$

but you have two semicircles, so you can just add the area of a circle to the area of the rectangle to get the total area

now, the diameter is 10m, which means that teh radius of a circle is 5m

$A_{total}= A_{rect} +A_{circ}$
$A_{total}= b*h + \pi r^2$

$A_{total} = 8*10 +\pi 5^2 =158.5$

Answer 2

Notice that the two semicircles have a radius of 10/2=5 and that their area is simply the area of a complete circle with a radius of 5.  In the center you have a rectangle that is 10 by 8.  So the total area is:

A=pr^2+xy

A=25p+80 m^2

A≈158.53 which is:

A≈158.5 m^2 (to the nearest tenth of a m^2)