3. $\frac{1}{2}$
3.【Solution】The volume of the right triangular prism is $\frac{1}{2} \times 1 \times 1 \times 1=\frac{1}{2}$ (cubic meters)
3. The figure on the right is the surface development of a right triangular prism, where the yellow and green parts are both squares with side lengths equal to 1. What is the volume of this right triangular prism?

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Translation:
3. The figure on the right is the surface development of a right triangular prism, where the yellow and green parts are both squares with side lengths equal to 1. What is the volume of this right triangular prism?