First you solve for the area of the unshaded triangle. Use the formula of area of triangle which is 1/2bh to find. 1/2(9)(4) = 18 cm^2. The area of the unshaded triangle is 18cm^2. Now we need to find the area of the rectangle. We can find that by using the formula for area of rectangle which is (b)(h). 12*4 = 48 cm ^2. Now that we have the area of the triangle and the area of the rectangle, we just need to subtract the area of the triangle from the area of the rectangle to get the area of the shaded region. 48 cm^2 - 18 cm^2 = 30 cm^2.
So our answer is: The area of the shaded region is 30 cm^2. In this case it’s option C or the third option for your quiz.
