Respuesta :

kn1f3

Answer:

y=7miles

Step-by-step explanation:

The total perimeter is 21 miles and we know two sides of the triangle are 7 miles, or 14 miles together.

We need to know the one other side of the triangle, so we can subtract the 14 miles we know from the total 21 miles.

21-14=7miles

Answer:

y=7 mi

Step-by-step explanation:

If you know that each side of this triangle is 7 and they are each side is the same length, you can make an educated guess  that the answer is 7. If you need An easier method 7x3=21. a triangle has 3 sides so your answer would be 7