Question

Find the total surface area of the cuboids of length, breadth and height as given below
(i) 12 cm, 10 cm, 5 cm,
(ii) 5 cm, 3.5 cm, 1.4 cm.
(iii) 2.5 cm, 2m, 2.4 m
(iv) 8 m, 5m, 3.5 m

Answer 1

(1) length $=12$ cm breadth $=10$ cm height $=5$ cm

$TSA=2(lb+bh+lh)=2[12\times 10+10\times 5+5\times 12]$

$TSA=2[120+50+60]=2\times 230$

$[TSA=460c{m}^2]$

(2) length $=5$ cm breadth $=3.5$ cm height $=1.4$ cm

$TSA=2(lb+bh+lh)=2[5\times 3.5+3.5\times 14+1.4\times 5]$

$TSA=2[17.5+4.90+7.0]=2\left[29.4\right]$

$[TSA=58.8c{m}^2]$

(3) length $=2.5$ cm breadth $=2$ m height $=2.4$ m

$TSA=2(lb+bh+lh)=2[0.025\times 2+2\times 2.4+2.4\times 0.025]$

$TSA=2[0.05+4.8+0.0600]=2\left[4.91\right]$

(4) length $=8$ m breadth $=5$ m height $=3.5$ m

$TSA=2(lb+bh+lh)=2[8\times 5+5\times 3.5+3.5\times 8]$

$TSA=2[40+17.5+28.0]=2\left[85.5\right]$

$[TSA=171.0m^2]$