An octahedron is formed from two identical square based pyramids - OCR - GCSE Maths - Question 9 - 2019 - Paper 1

Given that the length of the side of each pyramid's square base is 5 cm:

$\text{Base Area} = 5^2 = 25 \text{ cm}^2$

Since the octahedron consists of two identical pyramids, the volume of one pyramid is:

$V_{pyramid} = \frac{1}{2} \times 60 = 30 \text{ cm}^3$

Now substituting the known values into the volume formula:

$30 = \frac{1}{3} \times 25 \times h$

To find the height $h$, we can rearrange the equation:

$h = \frac{30 \times 3}{25} = \frac{90}{25} = 3.6 \text{ cm}$