Before you begin to prove
Mike's answer, you want to make sure that you
understand some of the key vocabulary in
the problem. Remember that perimeter is the distance
measured around a figure and a rectangle is
a geometric shape with 4 sides and the opposite
sides are parallel. If you understand those
terms you should be able to prove Mike correct.
Know your vocabulary!
There are different approaches you could take
to prove Mike correct. You could make a simple
drawing of the rectangle and substitute the
length with 24 cm and work from there basically
checking Mike's work and seeing if it works.
You could set the problem up using algebra
and seing what answer you would come up with.
There are different ways to answer this
one,
just make sure that with problems like this,
you are clear and specific with your explanation
staying focused on proving Mike correct.
Here is one way to prove Mike is correct with
his answer.
First draw a picture where you label the rectangle
based on the information you are given. In
this case your rectangle would have the width
or two short sides labeled with an X and the
two long sides be represented with 2X since
they are twice as long as the width.
You know that to find the perimeter, you add
the lengths of all the sides around the rectangle
and it equals 72 cm..
X + 2X + X + 2X = 72
Simplify the equation. 6X
= 72
Divide both sides by 6 to get X by itself. 6X
/ 6 = 72 / 6
Simplify. X = 12
You found that the width of the rectangle
is 12 cm. To find the length of the long sides,
you need to remember that the length is 2 times
the width, which is 12. Therefore, you know
that the length is 2 times 12 cm which is 24
cm.
Therefore Mike is correct with his answer.
Remember to be clear, specific, and focused
on proving Mike correct. Include all the steps
you went through, even your simple drawing
of the rectangle to help with your proof. |
