Question

The whole surface of a cuboid is 846 cm²
if the ratio & its length, breath and
height is 3:4:5, then find the length,
breath and height of the cuboid.​

Answer 1

Answer:

Step-by-step explanation:

take length as 3x

take breadth as 4x

take height as 5x

3x*4x*5x=846

60x=846

x=846/60

x=14.1 cm

hence length = 3x= 14.1*3=42.3 cm

breadth = 4x= 14.1*4=56.4 cm

height = 5x= 14.1*5=70.5 cm

Answer 2

Given,

Ratio of LENGTH : BREADTH : HEIGHT =

5 : 4 : 3

Given,

$\rm T.S.A = 2 ( LB + BH + LH )$

LET x be taken common,

Therefore,

$\implies\rm 846 = 2 ( 5x \times 4x + 4x \times 3x + 3x \times 5x )$

$\implies\rm 846 = 2 \times 20 {x}^{2} + 12 {x}^{2} + 15 {x}^{2}$

$\implies\rm 846 = 2 \times 47 {x}^{2}$

$\implies\rm 846 = 94 {x}^{2}$

$\implies\rm 9 = {x}^{2}$

Therefore,

$\implies\rm x = 3$

Now substituting the value of x we get =

$\implies\rm LENGTH = 5 × 3 = 15 cm$

$\implies\rm BREADTH = 4 × 3 = 12 cm$

$\implies\rm HEIGHT = 3 × 3 = 9 cm$