Question

Find the area of a triangle whose vertices are (1,-1), (3,5 ) and (2,7)​

Answer 1

Answer:

Area of triangle=

2

1

∣(x

1

(y

2

−y

3

)+x

2

(y

3

−y

1

)+x

3

(y

1

−y

2

))∣ where x=1,x

2

=3,x

3

=5, y

1

=2,y

2

=7,y

3

=3

⇒

2

1

∣(1(7−3)+3(3−2)+5(2−7))∣

⇒

2

1

∣(1−(4)+3(1)+5(−5))∣

⇒

2

1

∣(4+3+(−25)∣

=

2

1

∣(−25+7)∣

=

2

1

∣(−18)∣

Area of triangle =9 cm.