THE VOLUME OF A CUBOID IS 14400 cm3 AND ITS HEIGHT IS 15cmthe crosssectionofthe uboidisarectanglehavingitssidesintheratio5:3findtheperimeterofthe crosssection

Question

THE VOLUME OF A CUBOID IS 14400 cm3 AND ITS HEIGHT IS 15cm .the cross section of the cuboid is a rectangle having its sides in the ratio 5:3 find the perimeter of the cross section

Answer 1

Hi Arghadeep,

 

Volume of a Cuboid = length* width*height

 

let length of a cuboid = 5x cm & width= 3x cm,Volume of a cuboid = 14400 cm³ ,Height ^=15cm

 

substituting in formula,

 

14400 = 15*5x*3x

14400 =x²

15*15

 

taking square root on both sides, we get

120/15 =x

8= x

 

so length of a cuboid ( rectangula) =5*8=40cm

  width of a cuboid (rectangular)=3*8 =24 cm

 

Perimeter of a cross section= 2(l+w) = 2(40+24)=2(64)=128cm