C=15+3. Combine like terms. C=18.
Welp someone already answered and I just gotta answer questions so goodluck :)
Answer:

Step-by-step explanation:
Given




Required
The perimeter
To do this, we first calculate the side lengths using distance formula

So, we have:








The perimeter is:



Answer:
4
Step-by-step explanation:
using





Answer:
1 - SSS
Step-by-step explanation:
We need either two sides one angle, two angles one side, or three sides to prove congruency. In this case we have 3 sides so therefore this is congruent by the SSS theorem.