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

A. 21 units

B. 15 units

C. 34 units

D. 36 units

Step-by-step explanation:

A - C = (-2, 9) - ( - 2 - 3)

= (0, 12)

AC = 12

B - C = (7 - 3) - ( - 2 - 3)

= (9, 0)

BC = 9

ABC is a right - angled triangle with AC as the hypotenuse

AC = sqrt (9^2 + 12^2)

= sqrt (81 + 144)

= srqt (225)

= 15

Perimeter = 12 + 9 + 15

= 36 units

So the answer is 36 units

36units

Step-by-step explanation: A - C = (-2, 9) - ( - 2 - 3)

= (0, 12)

AC = 12

B - C = (7 - 3) - ( - 2 - 3)

= (9, 0)

BC = 9

ABC is a right - angled triangle with AC as the hypotenuse

AC = sqrt (9^2 + 12^2)

= sqrt (81 + 144)

= srqt (225)

= 15

Perimeter = 12 + 9 + 15

= 36 units

So the answer is 36 units