The area of a triangle is
\(Base * Height * \frac{1}{2}\)
so for the smaller triangle we have
\(2cm * 6cm *\frac{1}{2}\)
equals
6 cm squared
The second triangle is
\(3cm * 7cm * \frac{1}{2}\)
equals
\(10 \frac{1}{2}\)
squared inches and the diffrence is subtracting the smaller traingle from the bigger one whih equals
\(4 \frac{1}{2}\)
.