Help me..
prove it

Tan20°×tan40°×tan60°=3​

Tan20°×tan40°×Tan60°=3

Tan60×tan40°tan20°)

√3((2tan20°)/(1-tan²20))tan20

√3(2tan²20/(1-tan²20°)

2√3((sin²20/cos²20)/((cos²20-sin²20)/cos²20))

2√3(sin²20/(cos²20-sin²20))

2√3(sin²20/(1-2sin²20)

2√3sin²20/2cos²40

√3