Answer: the length of the first side is 25 cm.
the length of the second side is 50 cm.
the length of the third side is 65 cm.
Step-by-step explanation:
Let x represent the length of the first side of the triangle.
The length of the second side is twice the length of the first side. It means that the length of the first side is 2x.
the length of the third side is 10 less than three times the length of the first side. It means that the length of the third side is
3x - 10
The formula for determining the perimeter of a triangle is
Perimeter = a + b + c
Where a, b and c are the lengths of each side of the triangle. The perimeter of the triangle is 140 cm. It means that
x + 2x + 3x - 10 = 140
6x = 150
x = 150/6
x = 25
The length of the second side is
25 × 2 = 50 cm
The length of the third side is
25 × 3 - 10 = 65 cm