Question 757539: A couple of girls go for a horse race clockwise around the outside of a rectangular field.
The rectangular field has 'a' as the shortest side and 'b' as the long side of a rectangle.
Mary runs all around the field for a total of 20km. Annabelle only gets half way along the first side marked with 'b' before cutting straight across the field, before heading back to the start. She in total rides for 16 km. What are the dimensions of the field?
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! A horse race clockwise around the outside of a rectangular field.
The rectangular field has 'a' as the shortest side and 'b' as the long
side of a rectangle.
Mary runs all around the field for a total of 20km. Annabelle only
gets half way along the first side marked with 'b' before cutting
straight across the field, before heading back to the start.
She in total rides for 16 km. What are the dimensions of the field?
:
Mary's perimeter
2a + 2b = 20
Simplify, divide by 2
a + b = 10
:
Anna's perimeter
2a + 2(.5b) = 16
simplify, divide by 2
a + .5b = 8
:
Using eliminatation
a + b = 10
a +.5b = 8
------------ subtracting eliminates a, find b
0 + .5b = 2
b = 4; (multiplied by 2)
then
a + 4 = 10
a = 6; (subtracted 4 from both sides)
:
4 by 6 is the dimensions
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