Finding the area??

A = (B+b)*h/2

Area = (34.5 + 7.5)*11/2 = 42*11/2 = 231 mm^2

answer [A] 231 mm^2

a = (top base + lower base) * height/2

(7.5 + 34.5) x 11/2
= 42 x 11/2
= 462/2
= 231 square millimeters
(answer A)

To find the area of a trapezoid, let
a = length of the top
b = length of the bottom
h = height

Area = (a + b)/2 * h

For the trapezoid in question,
a = 7.5 mm
b = 34.5 mm
h = 11.0 mm

(7.5 + 34.5)/2 * 11
42/2 * 11
21 * 11 = 231 mm^2

I don't have time to do the math, but do the following steps:
1. Divide shape up into triangle then rectangle then another triangle.
2. Find area of each (triangle = 1/2 base * height and rectangle = length * width)
3. Add areas together

The first triangle you can kind of see with the dashed line of 11mm. The second triangle is the same thing but on the other side. For the triangle areas, you will want to find the base of the two triangles by doing (34.5 - 7.5) / 2. (we have the base of the whole thing but only want the two parts that are in the triangles)

1/2(34.5+7.5) 11
=42/2(11)
=21(11)=231 (A)

answer: 231

Area of a Trapezoid
A=1/2h(b-one + b-two)
A=1/2(11)(7.5+34.5)
A=231