What is the perimeter of a triangle with corners at (3 ,7 ), (1 ,3 ), and (4 ,9 )?

1 Answer
May 18, 2017

= 6 sqrt5 unit

Explanation:

Let say A(3,7), B(1,3) and C(4,9)
The distance D, between 2 point (x_1,y_1) and (x_2, y_2) is given by

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

therefore,
the distance between A& B = sqrt((3-1)^2 +( 7-3)^2) = sqrt 20

the distance between B&C = sqrt((1-4)^2 +( 3-9)^2) = sqrt 45

the distance between C&A = sqrt((4-3)^2 +( 9-7)^2) = sqrt 5

Total perimenter,
= sqrt20 + sqrt 45 + sqrt 5

= sqrt(4*5) + sqrt(9*5) + sqrt5

= 2 sqrt(5) + 3sqrt(5) + sqrt5
= 6 sqrt5 unit