Question

The area of the base of a prism is 21 cm2. The perimeter of the base is 20 cm. The height of the prism is 8 cm.



What is the surface area of the prism?

Answer 1

what is the shape of prism?

Answer 2

there is no shape that they gave me

Answer 3

let it be rectangular and x and y be its sides.
2(x+y)=20
x+y=20/2=10
y=10-x
xy=21
x(10-x)=21
10x-x^2=21
x^2-10x+21=0
x^2-7x-3x+21=0
x(x-7)-3(x-7)=0
(x-7)(x-3)=0
either x-7=0,x=7,y=10-7=3
or x-3=0,x=3,y=10-3=7
so length =7 cm
breadth=3 cm
surface area=2*21+20*8=? cm

Answer 4

496

Answer 5

42+160=?