Practice Boundary in Math

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

Quick Recap

The edge or outline that separates the interior of a region from its exterior; the set of points on the dividing border.

A fence around a yardβ€”it marks exactly where 'inside the yard' ends and 'outside' begins.

Showing a random 20 of 50 problems.

Example 1

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A 10 m by 6 m rectangle has a 2 m square cut out of one corner. Find the boundary length of the resulting L-shape.

Example 2

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A 12 m by 8 m yard has a square 3-by-3 m flowerbed inside it. What is the total boundary length, including the flowerbed?

Example 3

easy
What is the length of the boundary of a square with side 6 cm?

Example 4

easy
Which has a longer boundary: a circle of radius 5 or a circle of radius 2?

Example 5

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Two rectangles share one common 4 m edge. Rectangle A is 4 by 6 m, rectangle B is 4 by 5 m. What is the perimeter of the combined region?

Example 6

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A closed curve divides the plane into how many regions (besides the curve itself)?

Example 7

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A square garden has side 8 m. A path of width 1 m runs along the inside boundary. What is the inner edge's length?

Example 8

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The region RR is defined by the inequalities xβ‰₯0x \geq 0, yβ‰₯0y \geq 0, and x+y≀6x + y \leq 6. Describe the boundary of RR and find its perimeter.

Example 9

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A 5 cm by 8 cm rectangle has fencing along its boundary at \$3 per cm. What is the cost?

Example 10

challenge
A rope of length 40 m is shaped into a closed curve enclosing maximum area. What is the shape and the area (use Ο€β‰ˆ3.14\pi\approx 3.14)?

Example 11

challenge
Explain why the boundary of a region is itself a closed curve (has no boundary of its own), for a simple 2D region.

Example 12

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Why is the boundary of a region one dimension lower than the region itself?

Example 13

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A T-shape has top bar 8 wide, 2 tall and a vertical stem 3 wide, 6 tall centered below. Find its boundary length.

Example 14

hard
Among all rectangles with area 36, which has the smallest boundary length?

Example 15

easy
True or false: a point is part of the boundary if it is strictly inside the shape.

Example 16

challenge
Why can two regions have the same area but very different boundary lengths?

Example 17

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Does a region always have to be enclosed by a single boundary curve?

Example 18

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What is the dimension of the boundary of a 3D solid?

Example 19

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A right triangle has legs 6 and 8. Find its boundary length.

Example 20

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An L-shaped region is made by removing a 2Γ—2 square corner from a 6Γ—6 square. Find the perimeter (boundary length).