Explanation
the area of a a triangle is given by:
[tex]\text{Area}_{triangle}=\frac{base\cdot height}{2}[/tex]then
Let
base=6 cm
height=12 cm
now, replace
[tex]\begin{gathered} \text{Area}_{triangle}=\frac{base\cdot height}{2} \\ \text{Area}_{triangle}=\frac{6cm\cdot12\text{ cm}}{2} \\ \text{Area}_{triangle}=\frac{72\operatorname{cm}}{2} \\ \text{Area}_{triangle}=36cm^2 \end{gathered}[/tex]I hope this helps you