Peter is making an "X marks the spot" flag for a treasure hunt. The flag is made of a square white flag with sides of 12 centimeters. He will make the "X" by stretching red ribbon diagonally from corner to corner. How many centimeters of ribbon will Peter need to make the "X"?

Round your answer to the nearest centimeter.

34 cm

Step-by-step explanation:

Hi, since the situation forms 2 right triangles (see attachment) we have to apply the Pythagorean Theorem (to one triangle)

c^2 = a^2 + b^2  

Where c is the hypotenuse of the triangle (in this case the distance between corners) and a and b are the other sides.  

Replacing with the values given:  

c^2 = 12^2 + 12^2  

c^2 =144+144  

c^2 = 288

c = √288

c = 16.97 cm = 17 cm (rounded)

The other diagonal has the exact same lenght (because the flag is a square)

So, we have to multiply the length of the ribbon by 2:

17 x2 = 34 cm

Feel free to ask for more if needed or if you did not understand something.