Answer:
≈ 38.9%
Step-by-step explanation:
The perimeter of the triangle is the sum of the 3 sides, that is
perimeter = 6 + 7 + 5 = 18 cm
Then the 7 cm side as a fraction of the perimeter is
[tex]\frac{7}{18}[/tex]
To convert a fraction to a percentage , multiply the fraction by 100%
[tex]\frac{7}{18}[/tex] × 100% = 0.388.... × 100% ≈ 38.9% ( to 1 decimal place )