Question

Three sides of a triangle are of lengths 12.4 centimetres, 8.3 centimetres and 15.9 centimetres. Find the perimeter.

Answer 1

The lengths of the sides of the triangle are 12.4 cm, 8.3 cm and 15.9 cm.

The lengths can also be written as:

12.4 cm = 12 cm + 4 mm

8.3 cm = 8 cm + 3 mm

15.9 cm = 15 cm + 9 mm

We know that the perimeter of a triangle is equal to the sum of the lengths of all its sides.

∴Perimeter of the given triangle = 12.4 cm + 8.3 cm + 15.9 cm

The addition can be shown as follows:

		cm		mm
		12		4
		8		3
+		15		9
		36		6

Therefore, the perimeter of the triangle is 36 cm and 6 mm, i.e. 36.6 cm.