Circle questions can often look intimidating in Primary Math, especially when they involve a combination of different shapes and shaded regions. Many students immediately search for a formula, but some challenging PSLE Mathematics questions require more than just applying a formula. The key is learning how to see the hidden relationship between different shapes.

In the figure, there is a circle and two semi-circles placed within a square. At first glance, the question looks complicated because the usual formulas for finding the perimeter of familiar shapes do not seem to apply directly. However, by breaking the diagram into smaller parts and rearranging the curved sections, the solution becomes much simpler.
The important concept to understand is that the curved edges of the shaded parts can be combined to form the circumference. Instead of calculating each semi-circle separately, students can recognise how the different parts fit together and use their understanding of circles to solve the question efficiently.
This problem-solving technique is useful for many Primary Math and PSLE questions involving circumference and perimeter of shaded parts. Developing the ability to identify patterns and connect different concepts helps students become more confident learners when facing unfamiliar Mathematics problems.
For students who need further guidance, Superstar Teacher provides instant homework help and on-demand homework help through mentor support, allowing learners to receive explanations and build stronger problem-solving skills whenever they need help.
Continue reading to view the step-by-step solution from a real student question and see how the mentor breaks down this challenging question.
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