What is the orthocenter of a triangle with corners at (3 ,1 ), (1 ,3 ), and (5 ,2 )#?

1 Answer
Oct 8, 2016

The orthocenter is at the point (4/3, -17/3)

Explanation:

Let's begin by writing the equation of the line that goes through point (3,1) and perpendicular to the line going through points (1,3) and (5,2).

The slope, m, of the line going through points (1,3) and (5,2) is:

m = (3 - 2)/(1 - 5) = -1/4

The slope, n, of any line perpendicular is

n = -1/m = 4

Use point slope form of the equation of a line to obtain the equation of a line that we desire:

y - y_1 = n(x - x_1)

y - 1 = 4(x - 3)

y - 1 = 4x - 12

y = 4x - 11

Write the equation of a line that goes through point (5,2) perpendicular to the line through the points (3,1) and (1,3):

The slope, m, of the line that goes through the points (3,1) and (1,3) is:

m = (3 - 1)/(1 - 3) = 2/-2 = -1

The slope, n, of any line perpendicular is:

n = -1/m = 1

Again, Use the point slope form for the point (5,2):

y - y_1 = n(x - x_1)

y - 2 = 1(x - 5)

y = x - 7

The orthocenter is at the intersection of these two lines:

y = 4x - 11
y = x - 7

x - 7 = 4x - 11

4 = 3x

x = 4/3

y = 4/3 - 7

y = -17/3

The orthocenter is at the point (4/3, -17/3)