Answer:
90 cm²
Step-by-step explanation:
The area of the shaded portion is the area of parallelogram ABCD minus the area of triangle EBC.
ABCD is a parallelogram with base 18 cm and height 10 cm.
A(parallelogram) = bh = (18 cm)(10 cm) = 180 cm²
EBC is a triangle with base 18 cm and height 10 cm.
A(triangle) = bh/2 = (18 cm)(10 cm)/2 = 180 cm²/2 = 90 cm²
shaded area = 180 cm² - 90 cm² = 90 cm²