Calculate the area of the trapezoid.
12 mm
5 mm
9 mm
_square millimeters

52.5 square millimeters.

Step-by-step explanation:

Area of a Trapezoid = (a+b/2)h

= (9+12/2)•5

=(21/2) • 5

= 10.5 • 5

= 52.5 square millimeters

hope this helps!

52.5 mm^2 (square millimeters)

Step-by-step explanation:

Just split the figure into two sections to make a rectangle, and a right triangle (This whole figure can be thought of as a composite figure)

Once that is done, you will notice that the length and width of the rectangle is 9mm by 5mm, and the triangle is 3mm by 5mm (because 12mm - 9mm is 3 mm, and the height of the triangle is shared with the width of the rectangle).

The area of a triangle is 1/2(base×height) [just as a triangle is half of a rectangle], so the area of the rectangle is (length × width).

Therefore the 9mm by 5mm rectangle has an area of 9×5 mm = 45 mm^2, and the 3mm by 5mm triangle has an area of 1/2(5×3) = 15/2 = 7.5 mm^2.

Add both areas to find the total area:

45mm^2 + 7.5mm^2 = 52.5 mm^2.

Or using the formula for the area of a trapezoid: A = h (b1 + b2) / 2

Where A is the area, b1 is the first base, b2 is the second base, and h is the height of the figure.

Given that our first base is 9, second base is 12, and our height is 5.

A = h ( b1 + b2 ) / 2 → A = 5 ( 9 + 12 ) / 2 → 5 ( 21 ) / 2 → 105 / 2 → 52.5

Then just put this quantity in mm^2 because it is the area of the figure in that unit.

→ 52.5 mm^2

b

step-by-step explanation: