To calculate the perimeters of the triangles, we first find the perimeter of each triangle.
For the smaller triangle with side lengths 2, 6, and 7: \[ \text{Perimeter} = 2 + 6 + 7 = 15 \text{ units} \]
For the larger triangle with side lengths 6, 18, and 21: \[ \text{Perimeter} = 6 + 18 + 21 = 45 \text{ units} \]
Now we can compare the perimeters:
- Smaller triangle perimeter: 15 units
- Larger triangle perimeter: 45 units
Next, let's calculate the ratio of the corresponding sides of the smaller triangle to the larger triangle.
The corresponding sides are:
- Smaller triangle side: 2 units → Larger triangle side: 6 units
- Smaller triangle side: 6 units → Larger triangle side: 18 units
- Smaller triangle side: 7 units → Larger triangle side: 21 units
The ratio for each pair of corresponding sides is: \[ \frac{2}{6} = \frac{1}{3} \] \[ \frac{6}{18} = \frac{1}{3} \] \[ \frac{7}{21} = \frac{1}{3} \]
In all cases, the ratio of the smaller triangle's side to the larger triangle's corresponding side is \( \frac{1}{3} \).
Thus, the answer for the ratio of the corresponding sides of the smaller triangle to the larger triangle is: \[ \text{Ratio} = \frac{1}{3} \]
Final Answer: \(\frac{1}{3}\).