A triangle has corners at #(2 ,4 )#, #(8 ,6 )#, and #(4 ,9 )#. How far is the triangle's centroid from the origin?

1 Answer
Mar 29, 2016

≈ 7.87 units

Explanation:

Given the vertices of a triangle A#(x_1,y_1),B(x_2,y_2),C(x_3,y_3)#

The centroid has coordinates :

# x_c = 1/3(x_1 + x_2 + x_3 ) : y_c = 1/3(y_1+y_2+y_3)#

For the vertices given :

#x_c = 1/3(2+8+4) = 14/3" and " y_c = 1/3(4+6+9) = 19/3#

the coordinates of the centroid # = (14/3 , 19/3) #

To calculate distance from origin use the #color(blue)" distance formula " #

# d = sqrt((x_2-x_1)^2 + (y_2-y_1)^2)#

since the origin has coordinates (0 , 0) the formula is simplified.

#rArr d = sqrt((14/3)^2 + (19/3)^2) #

# = sqrt(196/9 + 361/9) = sqrt(557/9) ≈ 7.87#