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If the mid-points of the sides of a triangle are (2,4), (1÷2,1÷7) ,and (5÷2,9÷2) , find the coordinates of the vertices of the triangle.​

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Let's denote the vertices of the triangle as A, B, and C. The given midpoints are for the sides AB, BC, and CA. The coordinates of the midpoints are as follows:

Midpoint of AB: (2, 4)
Midpoint of BC: (1/2, 1/7)
Midpoint of CA: (5/2, 9/2)

Now, let's find the coordinates of the vertices:

1. Coordinates of A: Twice the x-coordinate of the midpoint of BC minus the x-coordinate of the midpoint of CA, and similarly for the y-coordinate.

\(A = (2 \times \frac{1}{2} - \frac{5}{2}, 2 \times \frac{1}{7} - \frac{9}{2})\)

\(A = (-\frac{4}{2}, -\frac{18}{7})\)

\(A = (-2, -\frac{18}{7})\)

2. Coordinates of B: Twice the x-coordinate of the midpoint of CA minus the x-coordinate of the midpoint of AB, and similarly for the y-coordinate.

\(B = (2 \times \frac{5}{2} - 2, 2 \times \frac{9}{2} - 4)\)

\(B = (\frac{5}{2}, 9 - 4)\)

\(B = (\frac{5}{2}, 5)\)

3. Coordinates of C: Twice the x-coordinate of the midpoint of AB minus the x-coordinate of the midpoint of BC, and similarly for the y-coordinate.

\(C = (2 \times 2 - \frac{1}{2}, 2 \times 4 - \frac{1}{7})\)

\(C = (\frac{4}{2}, 8 - \frac{1}{7})\)

\(C = (2, \frac{55}{7})\)

Therefore, the coordinates of the vertices A, B, and C are:

\(A = (-2, -\frac{18}{7})\)

\(B = (\frac{5}{2}, 5)\)

\(C = (2, \frac{55}{7})\)
User Jonathan Williams
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