The image above is a rectangular prism.

To compute the area of a rectangular prism requires three essential parameters which are the length, width and height of the rectangular prism.

A = 2wl + 2hl + 2hw

Where;

A = Area of the rectangular prism

l = Length of the rectangular prism

w = Width of the rectangular prism

h = Height of the rectangular prism

Let’s solve an example;

Find the area of a rectangular prism with a width of 10 cm, a height of 17 cm and a length of 14 cm.

This implies that;

l = Length of the rectangular prism = 14 cm

w = Width of the rectangular prism = 10 cm

h = Height of the rectangular prism = 17 cm

A = 2wl + 2hl + 2hw

A = 2 x 10 x 14 + 2 x 17 x 14 + 2 x 17 x 10

A = 280 + 476 + 340

A = 1096

Therefore, the **area of the rectangular prism** is **1096 cm ^{2}.**

**Calculating the Length of a Rectangular Prism using the Area, Width and Height of the Rectangular Prism. **

l = ^{A – 2hw} / _{2 (w + h)}

Where;

l = Length of the rectangular prism

A = Area of the rectangular prism

w = Width of the rectangular prism

h = Height of the rectangular prism

Let’s solve an example;

Find the length of a rectangular prism with a width of 9 cm, a height of 12 cm and a Area of 250 cm^{2}.

This implies that;

w = Width of the rectangular prism = 9 cm

h = Height of the rectangular prism = 12 cm

A = Area of the rectangular prism = 250 cm^{2}

l = ^{A – 2hw} / _{2 (w + h)}

l = ^{250 – 2 x 12 x 9} / _{2 (9 + 12)}

l = ^{250 – 216} / _{2 (21)}

l = ^{34} / _{42}

l = 0.81

Therefore, the **length of the rectangular prism** is **0.81 cm.**