The sides of a triangle are in the ratio 4:5:5 and its perimeter is 168 m. Find the area of the triangle.

Step 1: Find the lengths of the sides
Step 1: Add all the terms in the ratio
EXAMPLE: 3 + 4 + 5 = 12
Step 2: Divide this sum by each term in the ratio
EXAMPLE; \frac{3}{12},
\frac{4}{12},
\frac{5}{12}.
Step 3: Multiply the fraction with the given perimeter. To find triangle sides
EXAMPLE: \frac{3}{12}* 30 = 7.5
\frac{4}{12}* 30 = 10
\frac{5}{12}* 30 = 12.5
Step 2: Recall the area formula of the triangle.
FORMULA: \sqrt{s(s - a)(s - b)(s - c)}
Where a, b and c are the sides of the triangle and
s = half the perimeter = \frac{1}{2} (a+b+c)
Step 3: Calculate the "s" value
EXAMPLE: \frac{1}{2} (a+b+c)
\frac{1}{2} (3 + 4 + 5)
s = 6
Step 4: Substitute all the values in the area of the triangle formula
EXAMPLE: A = \sqrt{s(s - a)(s - b)(s - c)}
A = \sqrt{ 6 (6 - 3)(6 - 4)(6 - 5)}
Step 5: Do some calculations to find area.
EXAMPLE: A = \sqrt{ 6 (3)(2)(1)}
A = \sqrt{36}
A = 6