True or false; if one figure has less area than another figure, the figure with the smaller area has the smaller perimeter?
in Geometry Answers by Level 1 User (480 points)

Your answer

Your name to display (optional):
Privacy: Your email address will only be used for sending these notifications.
Anti-spam verification:
To avoid this verification in future, please log in or register.

1 Answer

False, unless the figures are the same type.

 

EXAMPLE

Imagine a cross-section of a staircase with 5 steps, each with a tread and drop of 1 unit. So the height of the staircase is 5 units and its length is also 5 units. The perimeter of the cross-section is 5 units up (height) and 5 units along (length). There are 5 steps so each step counts for 2 units, making 10 units (imagine carpeting the steps). The total perimeter is 5+5+10=20 units. The angle of the staircase is 45º.

Now consider a right isosceles triangle, with equal sides x units long. The hypotenuse is x√2 units, so the perimeter is 2x+x√2=x(2+√2)=3.414x units approx.

The area of the triangle is x²/2 square units.

The area of the cross-section of the staircase is 1+2+3+4+5=15 square units.

If the perimeters are made equal, 3.414x=20, so x=20/3.414=5.858 units approx and the area of the triangle is 17.16 square units approx, bigger than the  area of the staircase cross-section, which is only 15 square units.

So, although the perimeters are the same the triangle has a larger area. It follows then that the figure with the smaller area (staircase) doesn’t have a smaller perimeter—in this case they have the same perimeter length. If we made the areas the same, the perimeter of the staircase would be greater than the perimeter of the triangle. So the statement is false, in general.

by Top Rated User (1.1m points)

Related questions

1 answer
1 answer
Welcome to MathHomeworkAnswers.org, where students, teachers and math enthusiasts can ask and answer any math question. Get help and answers to any math problem including algebra, trigonometry, geometry, calculus, trigonometry, fractions, solving expression, simplifying expressions and more. Get answers to math questions. Help is always 100% free!
87,542 questions
99,805 answers
2,417 comments
523,372 users