Posted by pretty on .
If two trapezoids have the same area, do they always have the same perimeter? Explain your thinking with words and diagrams.

Math 
Anonymous,
Go to en wikipedia
and type: Trapezoid
You can construct many trapezoides with some area but different perimeter.
Area of trapezoid=((a+b)/2)*h
Example:
a+b=10 h=6 A=30
a+b=2 h=30 A=30
a+b=12 h=5 A=30 
Math 
Helena,
No. You can construct many trapazoids with the same area with multiple side lengths, thus as perimeter is the addition of the outer side lengths of a figure, if two trapazoids have different side lengths but the same area, most of the time, the different side lengths will equal to different perimeters. Eg.
Trapazoid 1:
a=4 b=8 h=6
A=(a+b)xh/2)
=(4+8)x6/2)
=12x6/2
=72/2
=36units squared
side lengths=4 each
P=(a+b+side length)x2
=(4+8+4)x2
=16x2
=32units squared*
Trapazoid 2:
a=4 b=5 h=8
A=(a+b)xh/2
=(4+5)x8/2
=9x8/2
=72/2
=36units squared
side lengths=6&7
P=a+b+6+7
=4+5+6+7
=22units squred* 
Math 
ANONYMOUS,
i don't know

Math 
deez,
yes this is correct the answer is deez nutz

Math 
Tatiana,
If two trapezoids have the same area do they always have the same perimeter