Level:
Project ID:
1103101207
Accepted:
1
Clonable:
0
Easy:
0
Let \( ABCD \) be a regular tetrahedron with an edge length of \( 5\,\mathrm{cm} \). Let \( \varphi \) be the angle between the edge \( AD \) and the base plane \( ABC \) (see the picture). Choose the correct expression for \( \varphi \):
\( \cos\varphi=\frac{\sqrt3}3 \)
\( \mathrm{tg}\,\varphi=\sqrt3 \)
\( \mathrm{tg}\,\varphi=\frac{\sqrt3}3 \)
\( \cos\varphi=\sqrt3 \)