The first thing we should note here is that we are looking for the area, so we need to recall the formula for the area of a right-angled triangle:

Area = (base x height) / 2

Next we can input our values given in the question, into the formula:

Area = (10 x 4) / 2

       = 20

As we are looking for an area, we must have a unit of measurement in our answer, and as the base and height were measured in cm, we can say that the area of the triangle is 20cm².

So the answer is 20cm^2.