Math Problem Statement

Shapes A and B above are mathematically similar. The area of one surface of each shape is given. Work out the missing volume.

Solution

We are given two shapes, A and B, that are mathematically similar. The surface areas of their bases are provided, and we are tasked with determining the volume of shape B. Shape A’s volume is already given as 250π3cm3\frac{250\pi}{3} \, \text{cm}^3.

Approach:

  1. Surface Area Relationship: Since the two shapes are similar, the ratio of their corresponding areas is proportional to the square of the ratio of their corresponding linear dimensions (scale factor). The surface areas of their bases are:

    • Shape A: 25πcm225\pi \, \text{cm}^2
    • Shape B: 49πcm249\pi \, \text{cm}^2

    The ratio of their base surface areas is: SBSA=49π25π=4925\frac{S_B}{S_A} = \frac{49\pi}{25\pi} = \frac{49}{25}

    This is the square of the ratio of their linear dimensions (scale factor), so the scale factor kk is: k=4925=75k = \sqrt{\frac{49}{25}} = \frac{7}{5}

  2. Volume Relationship: The volumes of similar shapes scale according to the cube of the linear scale factor. Therefore, the ratio of the volumes of shapes B and A is: VBVA=(75)3=343125\frac{V_B}{V_A} = \left( \frac{7}{5} \right)^3 = \frac{343}{125}

    Now, using the volume of shape A, VA=250π3cm3V_A = \frac{250\pi}{3} \, \text{cm}^3, we can calculate the volume of shape B as follows: VB=VA×343125=250π3×343125V_B = V_A \times \frac{343}{125} = \frac{250\pi}{3} \times \frac{343}{125}

    Simplifying: VB=250×343π3×125=85750π375=343π3cm3V_B = \frac{250 \times 343 \pi}{3 \times 125} = \frac{85750 \pi}{375} = \frac{343 \pi}{3} \, \text{cm}^3

Thus, the volume of shape B is 343π3cm3\frac{343 \pi}{3} \, \text{cm}^3.

Would you like a further breakdown of any step or have additional questions?

Here are 5 related questions:

  1. What is the relationship between surface area and volume scaling in similar shapes?
  2. How would the formula change if we were given the heights of the shapes instead of the areas?
  3. Can this method be used for other types of shapes like pyramids or cones?
  4. How can we find the height of shape B using the given surface area and volume?
  5. What if the surface area of one shape were unknown—how could we approach this?

Tip: Always remember that when dealing with similar shapes, the ratio of areas scales with the square of the linear dimensions, and the ratio of volumes scales with the cube!

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Geometry
Similarity of Shapes
Surface Area
Volume Ratios

Formulas

Ratio of Surface Areas: S_B / S_A = (scale factor)^2
Ratio of Volumes: V_B / V_A = (scale factor)^3
Volume of Shape B: V_B = V_A * (343 / 125)

Theorems

Similarity of Geometric Shapes

Suitable Grade Level

Grades 10-12