The perimeter of triangle ABC is 168 cm. Calculate the sides of the triangle if their ratio is known CA: CB: BA = 5: 3: 4.

Decision:
the aspect ratio of the triangle and its perimeter are known.
From the ratio CA: CB: BA = 5: 3: 4 we get
5 + 3 + 4 = 12 is the number of parts of the perimeter of the triangle
168/12 = 14 (cm) is the length of one part of the triangle
We calculate the lengths of the sides of the triangle by the ratio.
CA = 5 * 14 = 70 (cm)
СB = 3 * 14 = 42 (cm)
BA = 4 * 14 = 56 (cm)
Answer: the sides of the triangle are CA = 70 cm, CB = 42 cm and BA = 56 cm.