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Answer:
18 square units because units is not described
Step-by-step explanation:
trigonometric fit:
when one side of a triangle is 3 and the other side of the triangle is 4, the big side is 5. so in this case, the dashed line means 3.
3 times 4 equals area of rectangle which is 12
3 times 4 divided by a 2 which is 6 is the half rectangle