GCSE Maths Practice: 3d-shapes-and-nets

Question 1 of 10

Calculate the surface area of a sphere given its radius.

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\( \begin{array}{l}\text{Find the approximate surface area of a sphere with radius } 5\,\text{cm}.\\ \text{Use } \pi \approx 3.14.\end{array} \)

Choose one option:

Always square the radius and multiply by 4π.

The formula for the surface area of a sphere is \(4 \pi r^2\). Plug in the radius value to calculate. Here, radius r = 5 cm, so compute \(4 \times 3.14 \times 25 = 314\,\text{cm}^2\). Remember to approximate \(\pi\) as 3.14 if required. Surface area calculations are essential for understanding real-world applications like paint needed to cover spherical objects or designing curved surfaces. Visualize the sphere and its continuous curved surface to better understand the formula and practice similar calculations for different radii.