Question

solve 29th question from the photo

Answer 1

lsa of cube=4a.a=4x10x10=400
lsa of cuboid=2(l+b)xh=2(12.5+10)x8=1080
(a)cuboid
tsa of cube=6xaxa=6x10x10=600
tsa of cuboid=2(lb+bh+hl)=610
(b)cube

Answer 2

given,
side of a cubical box=10cm
LSA=4a2
=4×10square
=400cm2
TSA=6a2
=6×10square
=600cm2

L=12.5,B=10,H=8
TSA=2(lb+bh+hl)
=2(12.5×10+10×8+8×12.5)
=2(125+80+100)
=2(305)
=610cm2
LSA=2H(L+B)
=2×8(12.5+10)
=16(13.5)
=216cm2

(1)therefore cubical box has greater lateral surface area
(2)thereforecubical box has smaller total surface area.

hope it helps........