Tolong jawab dong. Bantu plis. No 10 aja kok

a) sin 30 = 1/2 --> BD = 1
                              AD = 2
                               AB = √3

sin 45 = ¹/₂√2 ---> BC/ AB = √2/2
                                     BC = √2/2 x AB
                                           = ¹/₂ √6
                              
AC = BC
      = ¹/₂ √6

cos 45 = BF/BD
       BF = cos 45 x BD
             = ¹/₂√2 x 1
             = ¹/₂√2

EC = BF
      = ¹/₂√2

AC = BC
      = ¹/₂ √6

AE = AC - EC
      = ¹/₂ √6- ¹/₂√2
      = ¹/₂(√6-√2)

DF = BF
      = ¹/₂√2

EF = BC
      = ¹/₂ √6

DE = DF + EF
      = ¹/₂√2 + ¹/₂ √6
      = ¹/₂(√6+√2)

b) sin 75 = sin (45+30)
               = sin 45. cos 30 + cos 45. sin 30
               = sin 45. cos 30 + sin 45. sin 30
               = sin 45 ( cos 30+sin30)
               = ¹/₂√2 (¹/₂√3 + ¹/₂)
               = ¹/₄ √6 + ¹/₄√2
               = ¹/₄  (√6 +√2)

c) cos 75 = cos (45+30)
                = cos 45. cos 30 - sin 45. sin 30
                = cos 45. cos 30 - cos 45. sin30
                = cos 45 (cos 30 - sin 30)
                = ¹/₂√2 (¹/₂√3 - ¹/₂)
                = ¹/₄ √6 - ¹/₄√2
                = ¹/₄  (√6 - √2)

d) tan 75 = sin 75/ cos 75
               = ¹/₄  (√6 +√2) / ¹/₄  (√6 - √2)
               = (√6 +√2) / (√6 - √2)
               = (√6 +√2)(√6 +√2)/ (6-2)
               = (6+2√12+2) / 4
               = 8+4√3 / 4
               = 2+√3