Please check attached file to see if you mean the same triangle.
Basically, to find the area of a triangle, you are going to use the formula :
A = b × h where b is base, h is height.
2
others also use the formula: Area=1/2(bxh)
Based on the figure, we have 6.9 cm (base) and 4 cm (height) as given.
Let us work out on the area of the said triangle.
A= 6.9cm × 4cm
2
= 27.6cm²
2
A= 13.8 cm²
Hope this helps!