1 A ray of light traveling from air into crown glass strikes the surface at an angle of 30 degrees. What will the angle of refraction be

Mary used 1/7 of a spool of ribbon to complete 4 projects. she used the same amount of ribbon on each project. how much ribbon did she use on each project?

There are 15 plates and each plate is either 7 or 12 inches diameter. which systems of equations do you use to find the number of 7 inch plates, x and 12 inch plates, y

Through non-collinear points there is exactly one plane.