Find the perimeter of the polygon with vertices at (1, 3), (7, 3), (7, 7), and (4, 7). a) 18 units b) 20 units c) 13 units d) 22 units

Your answer is A) 18 units

(1,3),(7,3),(7,7), and (4,7)? 

(1,3) ---> (7,3) 

You remained at height y = 3, and went from x = 1 to x = 7, so horizontally you went 6 to the right. 

(7,3)>(7,7) 

x = 7 in the first and x = 7 in the second, you didn't walk anything in the x direction, your height y changed from 3 to 7, so you went vertically up 4. 

(7,7) --> (4,7) 

You height remained the same, you went from 7 to 4 in the x direction, that's 3 to the left. 

Finally, to get back to point (1,3) - (4,7) > (1,3), 3 to the left and 4 down, the diagonal being 5. 

6+4+3+5= 10 + 8 = 18.