Question

Calcule a área S do triângulo de vértices A, B e C , em cada caso:
a) A(-1,1), B(1,3) e C(4,0)
b) A(0,3), B(-2,-2) e C( 2,-1)
c) A(-3,3), B(3,2) e C( 2,-2)

Answer 1

Calcule a área S do triângulo de vértices A, B e C , em cada caso:

a) A(-1,1), B(1,3), C(4,0)

(-1,1,1)

(1,3,1)

(4,0,1)

ldetl = 12

area = det/2 = 6

b) A(0,3), B(-2,-2) ,C( 2,-1)

(0,3,1),

(-2,-2,1)

( 2,-1,1)

ldetl = 18

area = det/2 = 9

c) A(-3,3), B(3,2) , C( 2,-2)

(-3,3,1),

(3,2,1)

( 2,-2,1)

ldetl = 25

area = det/2 = 25/2