The area of a triangle is given by [tex] \frac{1}{2} bh[/tex].
From the given figure: The base of the bigger triangle is 6 units and the height is 3 units.
The base of the smaller triangle is 3 units and the height is 2 units.
The area of the big triangle is [tex] \frac{1}{2} \times6\times3=9\, square\, units[/tex]
The area of the small triangle is [tex] \frac{1}{2} \times3\times2=3\, square\, units[/tex]
The required fraction is [tex] \frac{3}{9} = \frac{1}{3} [/tex]
