First of all the Triangle is a right triangle. The vertical side is 2 units and the horizontal is three. Just count the squares. The question is, what is the length of AB?
You can use the Pythagorean Theorem.
AB^2 = AC^2 + BC^2
AB^2 = 2^2 + 3^2
AB^2 = 4 + 9
AB^2 = 13
Take the square root of both sides.
AB = sqrt(13)
The square root of 13 is between 3 and 4. In fact the calculator will tell you that it is 3.6 which rounds to 4 (or should). Let's see what the answer says.
P = 2 + 3 + 3.6
P = 8.6
Normally you would round this to 9, but in this case you don't. The best answer is 8, but this question has poor answers.
