Posted by Caroline on .
Jake has a 3 foot long peice of wood that he wants to make into a triangular frame. He cuts a peice off of the board that is 1 foot 5 inches long. From the remaining board he cuts off another peice that is 7 inches long. He now has 3 peices of wood. Will he be able to fit 3 peices together to make a triangle? Explain

Algebra 
drwls,
No, he can't. Since his first cut was in the middle, making one more cut cannot make two sides that exceed the length of the longest side. To form a triangle, no side can have a length that equals or exceeds the sum of the lengths of the other two sides.

Algebra 
Reiny,
drwls probably made an arithmetic error.
Jake starts with 36 inches, cuts off 17 inches, leaving 19 inches.
From that he cuts 7 inches, leaving 12
so his 3 pieces are 17, 7, and 12 inches.
The sum of any two of these exceeds the third side, so the triangle is possible. (ignoring any lengths lost due to the cuts) 
Algebra 
Ehsan,
Yeah he can
bec 1foot = 12inches
so the piece of wood has 3*12 36 inch long
so the first piece = 12+5=17 inch
the second piece = 7 inch
so the last piece = 36(7+17)=12 inch
so do the inequality of triangle (the sum of two sides must be greater than the remaining side)
to shortcut time and effort sum the smallest sides and see if the sum is greater than the biggest side
(12+7)>?17
19>17
then it can be triangle