Examples with solutions for Surface Area of a Cuboid: Data with powers and roots

Exercise #1

Express the surface area of the cuboid below in terms of a.

a

Video Solution

Step-by-Step Solution

To find the surface area of a cuboid, I need to identify its three dimensions from the diagram and apply the surface area formula.

From the SVG diagram labels, the three dimensions of the cuboid are:

  • Length: a2a^2
  • Width: a+2a + 2
  • Height: aa

The surface area formula for a cuboid with dimensions ll, ww, and hh is:
SA=2(lw+lh+wh)SA = 2(lw + lh + wh)

Let me calculate each face area:

  • Face 1 (length × width): a2(a+2)=a3+2a2a^2 \cdot (a+2) = a^3 + 2a^2
  • Face 2 (length × height): a2a=a3a^2 \cdot a = a^3
  • Face 3 (width × height): (a+2)a=a2+2a(a+2) \cdot a = a^2 + 2a

Now, applying the surface area formula:
SA=2[(a3+2a2)+a3+(a2+2a)]SA = 2[(a^3 + 2a^2) + a^3 + (a^2 + 2a)]
SA=2[2a3+3a2+2a]SA = 2[2a^3 + 3a^2 + 2a]
SA=4a3+6a2+4aSA = 4a^3 + 6a^2 + 4a

Therefore, the surface area of the cuboid expressed in terms of aa is 4a3+6a2+4a4a^3 + 6a^2 + 4a.

Answer

4a3+6a2+4a 4a^3+6a^2+4a

Exercise #2

Calculate X given that the surface area of the shape is 65.78 cm².

333555

Video Solution

Answer

3

Exercise #3

Find the surface of the cuboid

Video Solution

Answer

108 108