Answer 6.75 square cm.
Explanation:
Let us let length of the triangle to mean height of the triangle..
So the height h = 3 cm
Width will mean base width : w = 4.5 cm
The formula for the area of a triangle is A = (1/2)*h * w
A = (1/2)*(3cm) * (4.5cm) =(1/2)* 13.5 cm*cm
A = 6.75 cm*cm