Answer:
The area of the triangle in square millimeter is;

Step-by-step explanation:
We want to find the area of triangle with the given dimensions in square millimeters.
![\begin{gathered} b=9\operatorname{cm} \\ h=1.36\operatorname{cm} \end{gathered}]()
Recall that 1 cm equals 10 mm;
![\begin{gathered} 1\operatorname{cm}=10\operatorname{mm} \\ b=9\operatorname{cm}=90\operatorname{mm} \\ h=1.36\operatorname{cm}=13.6\operatorname{mm} \end{gathered}]()
The area of a triangle can be calculated using the formula;

Substituting the given values;
![\begin{gathered} A=(1)/(2)*90\operatorname{mm}*13.6\operatorname{mm} \\ A=612mm^2 \end{gathered}]()
Therefore, the area of the triangle in square millimeter is;
