Sunday, May 10, 2015

The midpoints of the sides of a triangle are (2,2), (2,3), (4,6). Find the equations of the sides.

First, we'll write the relations for calculating the
coordinates of the mid-point of a segment.


The coordinates
of M are:


xM=(x1+x2)/2


yM=
(y1+y2)/2


Now, we'll calculate the mid-point of the side
AB.


xM = (xA+xB)/2


2 =
(xA+xB)/2 => xA+xB = 4 (1)


yM=
(yA+yB)/2


2 = (yA+yB)/2 => yA+yB = 4
(2)


We'll calculate the mid-point of
AC:


xN = (xA+xC)/2


2 =
(xA+xC)/2 => xA+xC = 4 (3)


yN=
(yA+yC)/2


3 = (yA+yC)/2 => yA+yC = 6
(4)


We'll calculate the mid-point of
BC:


xP = (xB+xC)/2


4 =
(xB+xC)/2 => xB+xC = 8 (5)


yP=
(yB+yC)/2


6 = (yB+yC)/2 => yB+yC = 12
(6)


We'll subtract (3) from
(1):


 xA+xB-xA-xC = 0


xB - xC
= 0 (7)


We'll add (7) to
(5):


xB - xC + xB+xC = 8


We'll
eliminate like terms:


2xB =
8


xB =
4


But, from (7), xB - xC = 0 and xB = 4,
so:


4 - xC =
0


xC =
4


From  (3), xA+xC = 4 and xC = 4,
so:


xA+4 = 4


xA=
0


Now, we'll calculate the
coordinates yA, yB, yC.


We'll subtract (2)
from (4):


yA+yC-yA-yB =
2


We'll eliminate like
terms:


yC-yB = 2 (8)


We'll add
(8) and (6):


yC-yB+yB+yC =
12+2


We'll eliminate like
terms:


2yC =
14


yC =
7


But yB+yC = 12 and yC = 7,
so:


yB+7 =
12


yB =
5


From (2),  yA+yB = 4 and yB
= 5, so:


yA+5 =
4


yA =
-1


The coordinates of the
vertices of the triangle
are:


A (0,-1) , B(4,5) and
C(4,7).

No comments:

Post a Comment

Comment on the setting and character of "The Fall of the House of Usher."How does setting act as a character?

Excellent observation, as it identifies how the settings of Poe's stories reflect the characters of their protagonists. Whet...