Find the are of a triangle whose vertices are (1,2), (8,2), and (1,6)

Take the segment between the first two vertices to be the base of the triangle.
The length of the base is then 8 - 1 = 7.
The height of the triangle is then 6-2 = 4.
The area of the triangle is thus 7*4/2 = 14.
Hope that helps!