Let’s solve this step by step.
We are given a 3D shape that looks like a trapezoidal prism — it has two parallel trapezoid faces (front and back) and rectangular sides connecting them.
The dimensions given:
- The front face is a trapezoid with:
- Top base = 45 cm
- Bottom base = 60 cm
- Height of trapezoid = 20 cm
- The length (depth) of the prism = 80 cm
To find the
volume of any prism, we use:
> Volume = Area of the base × height (or length, depending on orientation)
In this case, the “base” is the trapezoid face, and the “height” of the prism is the 80 cm side going into the page.
---
Step 1: Find area of the trapezoid base
Formula for area of a trapezoid:
> Area = (top + bottom) ÷ 2 × height
Plug in the numbers:
Area = (45 + 60) ÷ 2 × 20
= (105) ÷ 2 × 20
= 52.5 × 20
=
1050 cm²
---
Step 2: Multiply by the length of the prism
Volume = Area of base × length
= 1050 cm² × 80 cm
=
84,000 cm³
---
Final Answer:
84000
Parent Tip: Review the logic above to help your child master the concept of volume of irregular objects worksheet.
