4sin 130/ sin65 *sin25

Question

4sin 130/ sin65 *sin25

Answer 1

4*sin(13*пи/18)/(sin(5*пи/36)*sin(13*пи/36))=8

Answer 2

4sin130°/sin65°*sin25°=(2sin65°*cos65°)/sin65°*sin25°=
=2cos65°*sin25°=2cos(90°-25°)*sin25°=2sin²25°