Tiffany C. answered • 05/07/20
NYU Graduate Elementary and Middle School Tutor
The formula for perimeter of a rectangle is 2l + 2w. l for length, w for width.
It says that the length is 10cm greater than half the width so it is represented by 10+1/2w.
Multiply 2 by (10+1/2w) because of the 2l in 2l + 2w. You should get 20+w.
Your width of one side is w, but since there's two, it's 2w.
Plug your 20+w and 2w into the formula. You should get (20+w) + 2w.
Combine the w's (like terms) to get 3w+20. Set it equal to 38 because that's the total perimeter. 20+3w=38
Subtract 20 from both sides to get 3w=18.
Solve for w by dividing both sides by 3. w=6
Your width is 6.
Read the problem again and now find the length.
Half the width is 3, add 10. Length is equal to 13.
You can check by doing 13+13+6+6. It equals 38. I hope this helps!
