The perimeter of a right-angled triangle is 60cm. The lengths of its sides are in the ratio 3:4:5. Work out the area of the triangle.

Draw out a diagram of a right angled triangle. As the lengths of the sides of the triangle are in the ratio 3:4:5, start off by saying each side is 3cm (a), 4cm (b) and 5cm (c) respectively, with 5cm being the side opposite the right angle. What is the perimeter of this triangle? 3+4+5=12The perimeter of the triangle is 60cm. By multiplying 12 by 5, 60 is given. What we do to one side of the equation, we do to the other. Therefore, 3(5) = 15 4(5) =20 5(5)=25We have now found the lengths of the sides of the triangle. To find the area of a right angled triangle, use equation A=1/2(base x height) or in this case: A= 1/2(axb) A=1/2(15X20) A=1/2(300) A= 150cm² Don't forget units!