Question

Find the area of the triangle defined by the coordinates (7, 1), (0, 10), and (9, 4). (To the nearest tenth)
A) 12.5 square units
B) 17.5 square units
C) 19.5 square units
D) 22.5 square units

Answer 1

Answer:

  C)  19.5 square units

Step-by-step explanation:

The area from coordinates can be computed as ...

  A = (1/2)|x1(y2 -y3) +x2(y3 -y1) +x3(y1 -y2)|

  = (1/2)|7(10 -4) +0(4 -1) +9(1-10)| = (1/2)|7·6 +9·(-9)|

  = (1/2)|-39| = 39/2 = 19.5

The area of the triangle is 19.5 square units.

Answer 2

Answer:

19.5

Step-by-step explanation:

Use the distance formula: d =  

(x2 - x1)2 + (y2 - y1)2

A =  

1

2

bh =  

1

2

(

13

)(3

13

) = 19.5