What you’ll learn
Volume with fractional edge lengths.
Key idea
Fractional edges do not change the volume rule; cancel only within valid products.
Keep exact rational multiplication across all three edges; missing length is volume divided by the known base area.
Worked example
Enter the exact value or ordered values in the format requested below.
A rectangular prism has perpendicular edges 2/3, 2, 8/3 cm. Enter its exact numerical volume in cubic centimeters.
- The known base edges give 2/3×2=4/3 cm².
- Multiply by the third edge: 4/3×8/3=32/9 cm³, keeping exact fraction products.
Answer: 32/9
Quick Check
Evaluate a worked attempt at volume with fractional edge lengths, identify the first invalid step, and provide the correction.
A student computes volume for prism edges 2/3, 4, 2/3 cm: Step 1: V=lwh. Step 2: 2/3×4=8/3. Step 3: 8/3×2/3=25/9 cm³. Locate the first invalid step and correct the product.