Question

Find the coordinates of the missing if endpoint

if B is the midpoint of AC.
Given Endpoint: C(9,2)
Midpoint: B(6,4)

O A(7.5, 3)
O A(3,6)
O A(1.5, 1)
O A(12, 0)

Answer 1

B. A(3, 6)

Explanation:

If B is the midpoint of AC, where the coordinate of the midpoint B is (6, 4) and endpoint C is (9,2). To get the other coordinates A, we will use the midpoint formula;

B(X,Y) = (x₁+x₂/2, y₁+y₂/2)

From the formula;

X = x₁+x₂/2 and Y = y₁+y₂/2

From the coordinaes given X = 6, Y = 4, x₂ = 9 and y₂ = 2

To get x₁:

From X = x₁+x₂/2

6 = x₁+9/2

cross multiply

12 = x₁+9

x₁ = 12-9

x₁ = 3

Similarly for y₁;

Y = y₁+y₂/2

4 = y₁+2/2

cross multiply

8 = y₁+2

y₁ = 8-2

y₁ = 6

Hence the coordinates of the missing endpoint A(x₁,y₁) is (3, 6)