Answer:
8
Explanation:
To find the perimeter, you must add the lengths of all sides.
In this question the perimeter is given, which is 63.
63 = 12 + 12 + 3x + 2x + 1 + x + 2
1. Add the numbers
63 = 12 + 12 + 3x + 2x + 1 + x + 2
12 + 12 + 1 + 2 = 27
63 = 27 + 3x + 2x + x
2. Combine Like Terms
63 = 27 + 3x + 2x + x
x = 1
3x + 2x + 1x = 6x
63 = 27 + 6x
3. Move Variable to the left
63 = 27 + 6x
63 = 6x + 27
4. Subtract 27 from both sides, the opposite of adding 27
63 = 6x + 27
63 - 27 = 6x + 27 - 27
36 = 6x
5. Divide by the same factor, the opposite of multiplying 6
36 = 6x
36/6 = 6x/6
6. Cancel out the 6s but leave the x
36/6 = 6x/6
x = 6
So, now that we know that x = 6 we can solve the expression, x + 2, to find out the length of the side BC.
6 + 2 = 8