Answer:
d. 12 units, 14 units, 10 units
Explanation:
The side lengths differ by 2 units from one to the next larger one:
(2t+2) - (2t) = 2
(2t+4) - (2t+2) = 2
So, you're looking for answer numbers that can make a sequence with differences of 2, and that add to 36. Only the last choice matches that description.
_____
You can solve this "directly" by adding up the side lengths and setting that result to the perimeter length.
(2t+2) + (2t+4) + (2t) = 36
6t +6 = 36 . . . . . collect terms
6t = 30 . . . . . . . . subtract 6
t = 30/6 = 5 . . . . divide by 6
The shortest side is 2t, so is 2·5 = 10 units. Only the last answer choice matches this.
Side lengths are 12 units, 14 units, 10 units.