Question

Find the area of the triangle QRS.

Answer 1

Answer:

Area of ΔQRS is 140 unit².

Step-by-step 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,

$Area=\frac{1}{2}\left |x_1(y_2-y_3)+x_2(y_3-y_1)+x_3(y_1-y_2)\right|$

$Area\:of\:\Delta\,QRS=\frac{1}{2}\left |-9(10-(-10))+6(-10-5)+2(5-10)\right|$

                               $=\frac{1}{2}\left |-9(20)+6(-15)+2(-5)\right|$

                               $=\frac{1}{2}\left |-180-90-10\right|$

                               $=\frac{1}{2}\left |-280\right|$

                               $=\frac{1}{2}\times280$

                               = 140 unit²

Therefore, Area of ΔQRS is 140 unit².

Answer 2

140 is the correct answer