Question

the sum of lenth breadth and depth of cuboid is 19cm and lenth of diagonal is 11cm find surface area of cuboid

Answer 1

according to the question,
l + b + h=19 cm
diagnol = 11cm
the perimeter of cuboid = 2(lb + bh +hl)
to relate them,we have the formula root( l^2 +b^2 +h^2)=diagnol
squaring on both sides,
l * l +b *b + h * h = 121
2lb + 2bh +2hl +l^2 +b^2 + h^2=121
we know that l + b + h=19 cm
so,
2lb + 2bh +2hl +(19)^2 =121
2lb + 2bh +2hl = 240
2(lb + bh +hl)=240
we know that the perimeter of cuboid = 2(lb + bh +hl) =240cm
thus the perimeter of cuboid =240 cm

hope it helps!!!!
 please mark as brainliest if it helped!!