GCSE Maths Practice: congruence-and-similarity

Question 9 of 10

This question tests recognition of shapes that are always similar. Understanding which shapes share similarity is fundamental in geometry.

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\( \begin{array}{l}\text{Which pairs of shapes are always similar?}\end{array} \)

Select all correct options:

Check angles and side ratios. Circles are always similar; squares too. Rectangles must have same ratio.

Similarity in geometry refers to shapes that have the same angles and proportional sides. All circles are inherently similar because they only differ in radius, keeping the same shape. All squares are similar since their sides are in proportion and angles remain right angles. Rectangles are only similar if their side ratios are the same; otherwise, they are not proportional. Random triangles may not be similar unless side ratios and angles align. This knowledge allows students to quickly identify similar figures in diagrams, solve proportionality problems, and apply scaling in practical contexts such as design, maps, and models. Mastering similarity recognition improves problem-solving efficiency and geometric reasoning skills, essential for GCSE success.