Question

I dont have a ruler and I need to complete this Choose a room you would like to decorate. Measure its length or width. This
measurement will be the length of your pennant string.
2. Choose a size of paper square to use. (Hint: Whole number side lengths will
make the calculations easier.)
3. Cut the square in half along the diagonal to form two paper triangles
(pennant flags).
4. Measure the length of the diagonal. Then use the Pythagorean Theorem to
find its exact length.
Can someone help me getting the measurements