SubArea: Metric propertiesLevel: CProject ID: 1103101207Accepted: 1Clonable: 0Easy: 0Let ABCD be a regular tetrahedron with an edge length of 5cm. Let φ be the angle between the edge AD and the base plane ABC (see the picture). Choose the correct expression for φ:cosφ=33tgφ=3tgφ=33cosφ=3