Question

If a,b,c,length,breadth,and height of a cuboid are such that a+b+c=10cm and a^2 +b^2 +c^2=40cm^2, find the surface area of a cuboid?

Answer 1

A+b+c=10
s.a.=100-40=60

Answer 2

Answer:

60 cm

Step-by-step explanation:

''The surface area of the cuboid = 2(ab + bc + ac).''

Given that a + b + c = 10  &  a² + b² + c² = 40 cm²

Find the square of a + b + c = 10.

$(a+b+c)^2=10^2 \\ \\ a^2+b^2+c^2+2(ab+bc+ac)=100$

Import the value of a² + b² + c² = 40 cm² at LHS.

$40+2(ab+bc+ac)=100$

Subtract 40 from both sides.

$2(ab+bc+ac)=100-40 \\ \\ 2(ab+bc+ac)=\underline{\bold{60}}$

So the surface area of the cuboid is 60 cm.