area of the triangle?

[uptowngirl92]

If a triangle in the xy-coordinate system has vertices at
(-2 , -3), (4, -3) and (28, 7), what is the area of the triangle?
30
36
48
60
65

[fiercepoint]

30

I think it helps to draw the triangle to help you visualize what it looks like. The line between coordinates (-2 , -3), (4, -3) is the base which is 6 units in length. Same y coordinates for both points is also a giveaway here. Now you need the height. Since the distance between x coordinates was the base, the height will be the distance between y coordinates, in this case -3 and 7, which is 10 units. Now just plug the values into the formula to find the area (10 x 6) / 2 = 30.

[xcusemeplz2009]

there are two ways to solve this
ist) direct application formula i.e area of a triangle with coordinate (x1,y1);(x2,y2) and (x3,y3) is
= 1/2[x1(y2-y3)+x2(y3-y1)+x3(y1-y2)]
putting values we can get area

2nd and more simpler way is to draw the triangle in xy plane and get the height and base and calculate
in this case h=10 and b=6
area=1/2bh=1/2*6*10=30