OG详解-OG4 数学1 Q22

Choice B is correct. The area,  A, of a triangle can be found using the formula A =1​2​bh , where b is the length of the base of the triangle and h is the height of the triangle. It’s given that the triangle is a right triangle. Therefore, its base and height can be represented by the two legs. It’s also given that the triangle has sides of length 2√2​, 6​√2, and √80​ units. Since √80​ units is the greatest of these lengths, it’s the length of the hypotenuse. Therefore, the two legs have lengths 2√2​ and 6​√2units. Substituting these values for b and h  in the formula A = 1​2​bh  gives A = 12​(2√2)(6√2​) , which is equivalent to A = 6√​4 square units, or A = 12 square units.
Choice A is incorrect. This expression represents the perimeter, rather than the area, of the triangle. Choice C is incorrect and may result from conceptual or calculation errors. Choice D is incorrect and may result from conceptual or calculation errors.