angle between line and plane

CA=CB
VA=VB=10 cm
△CAB and △VAB are isos. triangles.
G is the mid-point of AB.
VG is perpendicular to AB.

∴ ∠VGC is the angle between the line VG and the plane ABC.
The line VG is the line of greatest slope.

In rt∠△AGC, ∠ACG=50˚/2=25˚
cos∠ACG=CG/AC
cos25˚=CG/8cm
CG=7.2505 cm

In rt∠△VCG,
tan∠VGC=VC/CG=6/7.2505=0.8275
∠VGC=39.6087˚

∴ The angle between the line VG and the plane ABC is 39.61˚ (corr. to 2 d.p.)
The inclination of the line of greatest slope is 0.83 (corr. to 2 d.p.)