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23 votes
23 votes
A rectangle has a perimeter of 34 and an area of 60. Find its dimensions

User Philoye
by
3.0k points

1 Answer

23 votes
23 votes

Answer:

5 by 12

Explanation:

The area and perimeter formulas can be used to write simultaneous equations for the dimensions of the rectangle. Solving those will give the dimensions of a rectangle with area 60 and perimeter 34.

__

setup

The relevant formulas for area (A) and perimeter (P) in terms of length (L) and width (W) are ...

A = LW

P = 2(L +W)

Using the given information, we can find a quadratic in W that will tell us the dimensions.

34 = 2(L +W) ⇒ L = 17 -W

60 = LW = (17-W)(W)

W² -17W +60 = 0 . . . . . written as a quadratic in standard form

solution

This equation can be solved by factoring and using the zero product rule.

(W -12)(W -5) = 0

Values of W that make these factors zero are ...

W = 12 or W = 5

For W = 12, L = 17 -12 = 5.

For W = 5, L = 17 -5 = 12.

The dimensions of the rectangle are 5 by 12.

User Marian Gibala
by
2.7k points
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