A right-angled triangle has base 10cm and height 4cm. What is the area of the triangle?

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.