
Katia F. answered 06/08/22
Experienced Pedagogy Tutor Specializing in Writing
To answer this prompt, you first must define both "abstract" and "concrete" concepts. A concrete concept is something that has a basis in the physical world and can be experienced "through sensation/perception", such as a dog or lake. On the other hand, abstract concepts do not have this attribute, "such as truth" (Wiemer-Hastings & Xu, 2005; Connell & Lynott, 2012; Brysbaert, Warriner, & Kuperman, 2014).
Now, with these definitions in mind, we can choose the correct pairs. An apple is a concrete object because it exists in the physical world, but psychology does not, and therefore cannot be associated as a concrete concept. Justice is most certainly an abstract concept since it is an abstract action. Triangle could arguably be both an abstract or concrete concept given that it is an abstract concept in mathematics, however, it can be represented in the physical world. For this prompt, however, I would assume that triangle is an abstract concept.