**Definitions:**

**Double Square Millimeter** (abbreviations: **mm4, or mm 4**): is the SI derived unit of area moment of inertia, a geometrical property of an area which reflects how its points are distributed with regard to an arbitrary axis.

**Double Square Foot** (abbreviation: **ft4**): is an imperial unit and U.S. customary unit (non-SI, non-metric) of area moment of inertia, a geometrical property of an area which reflects how its points are distributed with regard to an arbitrary axis.

## How to Convert Double Square Millimeters to Double Square Feet

*Example: How many double square feet are equivalent to 84.78 double square millimeters?*

As;

1 double square millimeters = 1.1588438533152E-10 double square feet

84.78 double square millimeters = Y double square feet

Assuming Y is the answer, and by criss-cross principle;

Y equals 84.78 times 1.1588438533152E-10 over 1

(i.e.) Y = 84.78 * 1.1588438533152E-10 / 1 = 9.8246781884064E-9 double square feet

Answer is: 9.8246781884064E-9 double square feet are equivalent to 84.78 double square millimeters.

*Practice Question: Convert the following units into ft4:*

N.B.: After working out the answer to each of the next questions, click adjacent button to see the correct answer.

( i ) 67.87 mm4

( ii ) 21.03 mm4

( iii ) 25.08 mm4