Question

Find the area of the triangle QRS.

Answer 1

140 is the correct answer

Answer 2

Area of ΔQRS is 140 unit².

Explanation:

Given: Coordinates of ΔQRS, Q( -9 , 5 ) , R( 6 , 10 ) & S( 2 , -10 )

To find: Area of triangle ΔQRS

Area of triangle is given by following formula,

`Area=(1)/(2)\left |x_1(y_2-y_3)+x_2(y_3-y_1)+x_3(y_1-y_2)\right|`

`Area\:of\:\Delta\,QRS=(1)/(2)\left |-9(10-(-10))+6(-10-5)+2(5-10)\right|`

`=(1)/(2)\left |-9(20)+6(-15)+2(-5)\right|`

`=(1)/(2)\left |-180-90-10\right|`

`=(1)/(2)\left |-280\right|`

`=(1)/(2)*280`

= 140 unit²

Therefore, Area of ΔQRS is 140 unit².