Answer:
16 cm^2
Step-by-step explanation:
The sum of length and width is half the perimeter, so is 12 cm. Since the width is 4 cm, the length is 12 cm -4 cm = 8 cm.
The area of the rectangle is the product of length and width, so is ...
rectangle area = (8 cm)(4 cm) = 32 cm^2
The area of the triangle is half the area of the rectangle, so is 16 cm^2.
