Posted by IB student on .
I just need to know how to use the perimeter formula to work this out (dont give answer)
A rectangular certicate 8 in. by 10 in. will have a frame 1 1/2 in. wide surrounding it. What is the perimeter of the outside edge of the frame?

MathPerimeter 
Ms. Sue,
P = 2L + 2W
8 + 3 = 11
10 + 3 = 13
The outside of the frame is 11 by 13. 
MathPerimeter 
DrBob222,
I don't like the way the problem is stated. A 11/2" wide frame can never go around a certificate that is 8 x 10". Ms Sue has interpreted the problem the only way it makes sense. I think the problem should have said that a frame was placed around the certificate with a space of 11/2". (To make it even clearer it could have added, on each side as well as top and bottom of the certificate.)

MathPerimeter 
IB student,
Thanks! :)

MathPerimeter 
Sam,
A 167
p23