Quadrilateral Classification: Analyzing ABCD with Perpendicular Properties

To solve this problem, let's analyze the quadrilateral depicted:

• Step 1: Analyze the given quadrilateral's shape using its geometric features, noting potential symmetry and side equivalence.
• Step 2: Identify if the quadrilateral fulfills the characteristics of a deltoid, which involve pairs of adjacent sides being equal.
• Step 3: Determine if it is possible to accurately categorize the quadrilateral as a convex or concave deltoid based on the given image and without explicit measurements.
• Step 4: In the absence of direct measurable evidence, consider if categorization is feasible.

Assessing visuals alone can lead to assumptions about equal lengths or angles, but without numerical data, it's challenging to make definitive geometrical claims about sides or symmetry.

Given these limitations, it is reasonable to conclude that we cannot definitively prove whether the quadrilateral is a deltoid (convex or concave) using just the visual representation provided.

Therefore, the solution to the problem is "It is not possible to prove if it is a deltoid or not."