1. A design support apparatus comprising: a processor; and a memory that stores a plurality of instructions, which when executed by the processor, cause the processor to execute: determining a shape of a first ridge line that is provided in a first plane surface included in a three-dimensional model of a verification target and forms an entrance of a hole or a base of a projection in the first plane surface; extracting, from within the three-dimensional model, a first extracted graphic that includes a second ridge line coinciding with at least a portion of the shape of the first ridge line; creating a comparison-use vector to be compared with the direction of a normal vector of the first plane surface, in response to a type of the first extracted graphic; determining whether the first extracted graphic is a graphic forming a hole or a graphic forming a projection, in response to an angle between the normal vector and the comparison-use vector; determining whether the first extracted graphic is a hollow cylinder or a circular cone when a graphic formed by the first ridge line is determined to be a circle; creating the comparison-use vector headed from the center of the circle to the center of a circle formed by a facing ridge line facing the ridge line provided in the first plane surface when the first extracted graphic is a hollow cylinder; determining that the first extracted graphic is a graphic including a surface forming a projection when an angle between the normal vector and the comparison-use vector is 0 degrees; and determining that the first extracted graphic is a graphic including a surface forming a hole when the angle between the normal vector and the comparison-use vector is 180 degrees.