Please can someone help with this. Not sure where I am going wrong? Find the equation of the line joining points (1,9) and (3,1)

m=y2-y1/x2-1= 1-9/3-1=-8/2=-4

m= -4, a = 3, b= 1

y-b= m(x-a)
y-1=-4(x-3)
y-1=-4x+12
y= -4x + 11

He trapezoid is composed of a rectangle and two triangles. what is the area of the rectangle? what is the total area of the triangles? what is the area of the trapezoid? ? a) 42 cm2; 27 cm2; 69 cm 2 b) 54 cm2; 27 cm2; 81 cm 2 c) 108 cm2; 27 cm2; 135 cm 2 d) 108 cm2; 13.5 cm2; 121.5 cm 2