C = 2 pi r
but c = 15
15 = 2 pi r
15 = 2 * (22/7) * r
r = (15*7) / 2 / 22
r = 2.386
10 people because all the sisters have the same brother so 7+1+2.
Surface Area of the figure is 1208 square centimeters
a=20
b=13
c=12
d=5
e=8
Top face:
A1=a×e=20×8
ae=160
Bottom face:
A2(a+2d)×e=(20+2×5)×8=(20+10)×8=30×8
(a+2d)e=240
Front face:
Rectangle
a×c=20×12=240
Triangle:
12c×d=12×12×5=6×5=30
A3Rectangle +2 triangles
240+2×30=240+60=300
(a+d)c=300
Slant face:
A4=b×e=13×8=104
be=104
Total surface area
A=A1+A2+2(A3+A4)
A1=160
A2=240
A3=300
A4=104
Thus,
A=160+240+2(300+104)
A=400+2(404)
A=400+808=1208
Surface Area of the figure is 1208 square centimeters
If the insurance pays $2,000, but the test itself cost $2,750, you simply subtract.
$2,750-$2,000= $750
Therefore Bobby has to pay $750