Practice Geometric Optimization in Math

Use these practice problems to test your method after reviewing the concept explanation and worked examples.

Quick Recap

Finding the best geometric configuration — the shape that maximizes area, minimizes perimeter, uses the least material, or achieves some other optimal outcome — subject to given constraints.

What rectangle with fixed perimeter has the most area? A square!

Showing a random 20 of 50 problems.

Example 1

medium
A field with perimeter 80 m must be rectangular. If one side is constrained to be at least 25 m, find the dimensions maximizing area.

Example 2

easy
Two rectangles have the same perimeter of 24 cm: one is 8×4 cm and one is 6×6 cm. Which has greater area? Does this match the P2/16 maximum?

Example 3

hard
A poster has total area 384 cm2 with 4 cm margins on top and bottom and 2 cm margins on the sides. What dimensions of the poster maximize the printable area?

Example 4

medium
A rectangle is inscribed under the curve y=4−x2 on the x-axis, with its base on the axis. What is the maximum area?

Example 5

easy
Of all shapes enclosing a fixed area, which has the smallest perimeter?

Example 6

challenge
Among all triangles inscribed in a circle of radius 1, find the one with maximum area and give that area.

Example 7

easy
Of all rectangles with perimeter 40 inches, what is the smallest possible area (assuming positive sides)?

Example 8

easy
Of all rectangles with a fixed perimeter, which shape has the most area?

Example 9

easy
True or false: among all closed curves of length L, the circle encloses the largest area.

Example 10

easy
A rectangle has perimeter P=40 cm. Using the formula maximum area =P2/16, compute the maximum area and the dimensions of the optimal rectangle.

Example 11

medium
A farmer builds a rectangular pen against a straight wall (no fence needed on the wall side) with 40 m of fence. What dimensions maximize area?

Example 12

hard
A cylindrical can is open at the top and must hold V=500 cm3. What radius minimizes the material (lateral + base)?

Example 13

hard
An open-top box has a square base of side x and height h. If the total surface area equals 48 cm2, what is the maximum volume?

Example 14

easy
To use the least fencing for a fixed rectangular area, what proportions should the rectangle have?

Example 15

medium
A farmer has 40 m of fence for a rectangular pen. What dimensions maximize the area, and what is that area?

Example 16

easy
Using Amax⁡=P2/16, find the maximum area of a rectangle with perimeter P=24.

Example 17

hard
Find the rectangle of maximum area inscribed in the ellipse x2a2+y2b2=1 with sides parallel to the axes.

Example 18

hard
Find the largest area of an isoceles triangle inscribed in a circle of radius 1.

Example 19

medium
A square and a circle have the same perimeter P. Which has the larger area, and by what ratio?

Example 20

challenge
Among all rectangles inscribed in a semicircle of radius 1 (base on the diameter), what is the maximum area?