Acircular platform is to be built in a playground. the center of the structure is required to be equidistant from three support columns located at d(−2,−4), e(1,5), and f(2,0). what are the coordinates for the location of the center of the platform?

The coordinates for the location of the center of the platform are (-1 , 2)

Step-by-step explanation:

* Lets revise the equation of the circle

- The equation of the circle of center (h , k) and radius r is:

  (x - h)² + (y - k)² = r²

- The center is equidistant from any point lies on the circumference

 of the circle

- There are three points equidistant from the center of the circle

- We have three unknowns in the equation of the circle h , k , r

- We will substitute the coordinates of these point in the equation of

 the circle to find h , k , r

* Lets solve the problem

∵ The equation of the circle is (x - h)² + (y - k)² = r²

∵ Points D (-2 , -4) , E (1 , 5) , F (2 , 0)

- Substitute the values of x and y b the coordinates of these points

# Point D (-2 , -4)

∵ (-2 - h)² + (-4 - k)² = r² ⇒ (1)

# Point E (1 , 5)

∵ (1 - h)² + (5 - k)² = r² ⇒ (2)

# Point (2 , 0)

∵ (2 - h)² + (0 - k)² = r²

∴ (2 - h)² + k² = r² ⇒ (3)

- To find h , k equate equation (1) , (2) and equation (2) , (3) because

  all of them equal r²

∵ (-2 - h)² + (-4 - k)² = (1 - h)² + (5 - k)² ⇒ (4)

∵ (1 - h)² + (5 - k)² = (2 - h)² + k² ⇒ (5)

- Simplify (4) and (5) by solve the brackets power 2

# (a ± b)² = (a)² ± (2 × a × b) + (b)²

# Equation (4)

∴ [(-2)² - (2 × 2 × h) + (-h)²] + [(-4)² - (2 × 4 × k) + (-k)²] =

  [(1)² - (2 × 1 × h) + (-h)²] + [(5)² - (2 × 5 × k) + (-k)²]

∴ 4 - 4h + h² + 16 - 8k + k² = 1 - 2h + h² + 25 - 10k + k² ⇒ add like terms

∴ 20 - 4h - 8k + h² + k² = 26 - 2h - 10k + h² + k² ⇒ subtract h² and k²

  from both sides

∴ 20 - 4h - 8k = 26 - 2h - 10k ⇒ subtract 20 and add 2h , 10k

  for both sides

∴ -2h + 2k = 6 ⇒ (6)

- Do the same with equation (5)

# Equation (5)

∴ [(1)² - (2 × 1 × h) + (-h)²] + [(5)² - (2 × 5 × k) + (-k)²] =

  [(2)² - (2 × 2 × h) + k²

∴ 1 - 2h + h² + 25 - 10k + k² = 4 - 4h + k²⇒ add like terms

∴ 26 - 2h - 10k + h² + k² = 4 - 4h + k² ⇒ subtract h² and k²

  from both sides

∴ 26 - 2h - 10k = 4 - 4h  ⇒ subtract 26 and add 4h

  for both sides

∴ 2h - 10k = -22 ⇒ (7)

- Add (6) and (7) to eliminate h and find k

∴ - 8k = -16 ⇒ divide both sides by -8

∴ k = 2

- Substitute this value of k in (6) or (7)

∴ 2h - 10(2) = -22

∴ 2h - 20 = -22 ⇒ add 20 to both sides

∴ 2h = -2 ⇒ divide both sides by 2

∴ h = -1

* The coordinates for the location of the center of the platform are (-1 , 2)