The vertices of a triangle are #(2, 1), (2,5),# and #(5, 1)#. What is the area of the triangle?
2 Answers
Jan 6, 2018
Explanation:
#"given the vertices of a triangle "#
#(x_1,y_1),(x_2,y_2)" and "(x_3,y_3)#
#"then the area (A) is given by"#
#A=1/2|x_1(y_2-y_3)+x_2(y_3-y_1)+x_3(y_1-y_2)|#
#"let "(x_1,y_1)=(2,1),(x_2,y_2)=(2,5),(x_3,y_3)=(5,1)#
#A=1/2|2(5-1)+2(1-1)+5(1-5)|#
#color(white)(A)=1/2|8+0-20|#
#color(white)(A)=1/2|-12|=6#
Jan 6, 2018
Explanation:
this can also be calculated using determinant form
#for coordinates
in this case
simplifying the determinant by elementary row operations
expand by