2. (3 points) One of the heights of a triangle is 2 cm. If the height increases by 6 cm, with the base remaining unchanged, the area increases by 12 square cm. The area of the original triangle is $\qquad$ square cm.
【Solution】Solution: Let the base of the triangle be $a$ cm
$$
\begin{aligned}
a \times(2+6) \div 2-2 a \div 2 & =12 \\
4 a-a & =12 \\
3 a & =12 \\
a & =4 ;
\end{aligned}
$$

The area of the original triangle is $4 \times 2 \div 2=4$ (square cm)
Answer: The area of the original triangle is 4 square cm.
Therefore, the answer is: 4.