When a Steel Cookie Sheet Is Placed in an Oven $\Delta A = A _ { 0 } \gamma \Delta T$

When a steel cookie sheet is placed in an oven and heated, it expands due to the temperature change. The change in area of the cookie sheet is modeled using the following equation: $\Delta A = A _ { 0 } \gamma \Delta T$ where $\Delta A =$ change in area in $\mathrm { cm } ^ { 2 }$
$A _ { 0 } =$ original area in $\mathrm { cm } ^ { 2 }$
$\gamma =$ area coefficient of thermal expansion
$\Delta T =$ change in temperature in $C ^ { \circ }$ What is the appropriate unit for $\gamma$ if the preceding equation is to be homogeneous in units? a. $/ C ^ { \circ }$

b. $\mathrm { cm } ^ { 2 }$

c. $C ^ { \circ }$

d. cm