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What is the perimeter of ABC with vertices A (-2,9) , B (7,-3) , C (-2,-3) in the coordinate plane?

A. 21 units
B. 15 units
C. 34 units
D. 36 units

User Kelsmj
by
5.0k points

1 Answer

4 votes

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Answer:

D. 36 units

Explanation:

Using the distance formula, we find the length of AB to be ...

d = √((x2 -x1)² +(y2 -y1)²)

d = √((7-(-2))² +(-3-9)²) = √(81 +144) = √225 = 15

The line BC is horizontal, so its length is the difference of the x-coordinates:

BC = 7 -(-2) = 9

The line AC is vertical, so its length is the difference of the y-coordinates:

AC = 9 -(-3) = 12

The sum of the lengths of the sides of the triangle is ...

P = 15 + 9 + 12 = 36

The perimeter is 36 units.

User Rodrigo Salvo
by
5.6k points
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