Question

Find the tringle vertices (3.1) (-3.1) and(-3-2)

Answer 1

Correct Question :-

Find the area of triangle whose vertices are ( 3 , 1 ), ( -3 , 1 ) and ( -3 , -2 ).

Solution :-

Let the vertices of the triangle be A( 3 , 1 ), B(-3 , 1 ) and C ( -3 , -2 ).

$\boxed{\bf Area \ of \ triangle = \dfrac{1}{2} \times [ \ x_1(y_2-y_3)+x_2(y_3-y_1)+x_3(y_1-y_2) \ ]}$

Here :-

$\bullet \sf \ x_1= 3 \ , \ y_1= 1 \\\\\bullet \ x_2 = -3 \ , \ y_2= 1 \\\\\bullet \ x_3 = -3 \ , \ y_3 = -2$

Area of triangle ABC :-

$\longrightarrow \sf \dfrac{1}{2} \times [ \ 3(1-(-2))+-3(-2-1)+-3(1-1) \ ] \\\\\longrightarrow \dfrac{1}{2} \times [ \ 3(1+2)+-3(-2-1)+-3(1-1) \ ] \\\\\longrightarrow \dfrac{1}{2} \times [ \ (3 \times 3 ) +(-3 \times -3 )+(-3 \times 0 ) \ ] \\\\\longrightarrow \dfrac{1}{2} \times [ \ 9+9+0 \ ] \\\\\longrightarrow \dfrac{1}{2} \times [ \ 18 \ ] \\\\\longrightarrow \bf 9 \ sq.units$