Do you need a ruler or protractor?
1. Ruler
If you do not have a ruler here, try using a ruler on your smartphone.
The ruler can measure the length of things.
The length can be measured in inches, in centimeters (cm).
2. Protractor
If you do not have a protractor here, try the protractor with your smartphone.
The protractor can measure the angle of the object reflected by the camera.
Try various protractor apps and protractor apps.