Year 9 Maths; please help...?

The answer is the (.5 x 6 x square root of 27). You get the area of a triangle by (.5)(base)(height). The base is already known, but you don't have the height. you find the height through the Pythagorean Theorem: c^2 - b^2 = a^2. c=6, b=3. It becomes 36-9=27 Then square root 27 to make it about 5.2. Now to find the area: (.5)(6)(5.2) and you will get about 15.6m^2.