Question

Plz help me solving this question ​

Answer 1

Step-by-step explanation:

Q5:Find the length of each side of the cube whose Total surface area are given below:

(B)2400cm^2

Solution:

T.S.A= 6a^2 [ we have to find a]

2400=6a^2

2400/6=a^2

400=a^2

a=squareroot of 400

=20

So, 20cm is the length of a cube.

Answer 2

Answer:

Step-by-step explanation:

3) Surface area of cube = 6a² where a is side of the cube.

a)  a = 6 cm

Surface area of cube = 6 * 6*6 = 216 cm²

b) a = 4.5 cm

Surface area of cube = 6 * 4.5 * 4.5 = 121.5 cm²

4)  Area of cuboid = A = 2(lb + bh + hl)

a) l = 10 cm ; h = 6 cm  ; A = 376 cm²

  A = 376

2(lb + bh + hl) = 376

2(10b + 6b + 60) = 376

2*( 16b + 60) = 376

 2*16b + 2*60 = 376

     32b + 120 = 376

        32b  = 376 - 120

          32b = 256

             b = 256 / 32

b = 8 cm

5) Surface area  of cube = 150 cm²

6a² = 150

Divide both sides by 6

a² = 150/6

a² = 25 = 5*5

a = 5 cm

6)  l = 15 cm ; b = 12 cm ; h = 10cm

Lidless. so area of top portion is not included

Surface area of lidless cuboid = 2(hb + hl) + lb

                                                  = 2*(10*12 + 10*15) + (15*12)

                                                  = 2*(120 + 150) + 180

                                                  = 2* 270 + 180

                                                  = 540 + 180

                                                   = 720 cm²