The perimeter is the sum of the lengths of the sides of the triangle. The length of the side BC that is vertical can be found by finding the difference of y-coordinates:
BC = 5 -(-2) = 7
The lengths of the other two sides can be found using the given distance formula. Fill in the coordinate values and do the arithmetic.
AB = √((4-(-4))^2 +(5-(-1))^2) = √(8^2 +6^2) = √(64+36)
AB = √100 = 10
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AC = √((4-(-4))^2 +(-2-(-1))^2) = √(8^2 +(-1)^2) = √(64 +1)
AC = √65 ≈ 8.06
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So, the perimeter is ...
P = AB +BC +AC
P = 10 + 7 + 8.06 = 25.06 ≈ 25.1 . . . . matches choice B
