Final answer:
The true statement about geometric shape similarity is that all squares are similar because they have congruent angles and proportional sides. This is based on the definition that similar figures must have the same shape with proportional corresponding sides and congruent corresponding angles.
Step-by-step explanation:
The statement that is true regarding the similarity of geometric shapes is: A) All squares are similar because they all have corresponding sides proportional and all 4 angles are congruent right angles. This is true due to the definition of similarity in geometry which states that two figures are similar if they have the same shape, regardless of size, with corresponding angles being congruent and corresponding sides being proportional. Examples of this include all squares having four 90-degree angles and all sides of the same relative length to each other.
In contrast, not all right triangles are similar just because they have a right angle (Option B), since the other angles and sides may not be proportional. Similarly, not all isosceles triangles are similar just because they have two congruent angles (Option C); they also need to have sides that are proportional. Lastly, rectangles are not similar simply because they have four right angles (Option D), since the ratio between the lengths of adjacent sides can differ.
The correct understanding of similarity is important when applying geometric theorems such as the Pythagorean Theorem, which states that the square of the hypotenuse (c) is equal to the sum of the squares of the other two sides (a and b) in a right triangle, shown by the equation a² + b² = c². The Pythagorean Theorem is a fundamental concept in trigonometry and mathematics overall.