The perimeter of is _____.

A.23.4 mm
B.25.4 mm
C.27.4 mm
D.32.4 mm

B. 25.4mm

Step-by-step explanation:

The answer is 25.4 mm. hope this helps, have a great day/night, stay safe, and merry christmas!

When variables are touching, that means after plugging them in, we multiply.
So the equation becomes 13 + axb 
Lets fill a and b in:
13+(2.5)(3)
In the order of operations (or PEMDAS),we must multiply first. 
2.5 x 3 =7.5
Then the equation becomes:
13 + 7.5
No you just add to get your answer which is (B)20.5
Hope this helps!