The perimeter of a right-angled triangle is 72 cm. The lengths of its sides are in the ratio 3 : 4 : 5 Work out the area of the triangle.
Work out the lengths of each side; do so by adding the ratio components together (3+4+5).The components add to 12; we can now find the value of a single unit of the ratio, by dividing 72 by 12.72/12 is 6; each part of the ratio needs to be multiplied by 6 to get the final side length.3 x 6 = 18cm4 x 6 = 24cm5 x 6 = 30cmYou can check this is correct by adding up all the new lengths; 18 +24+30 = 72, so this is correct!Now, if you draw the right angled triangle and label it, use the area = (base x height)/2 formula to work out the area.The diagonal side of a triangle is always the longest, so that length is 30cm . l . 24cm l . 30cm Therefore, the area of the triangle is (18x24)/2, the same as (18x12). The area is 216cm2 l . l________ . 18cm
