Tolong di bantu ya kakak2 sekalian

Tolong di bantu ya kakak2 sekalian

${a}^{2} + {c}^{2} = {1}^{2} \ {c}^{2} = 1 - {a}^{2} \ \ {b}^{2} + {c}^{2} = {4}^{2} \ {b}^{2} + (1 - {a}^{2} ) = 16 \ {b}^{2} - {a}^{2} = 16 - 1 \ {b}^{2} - {a}^{2} = 15 \ {b}^{2} = 15 + {a}^{2} \ \ {d}^{2} + {a}^{2} = {7}^{2} \ {d}^{2} = 49 - {a}^{2} \ \ OK = sqrt{ {b}^{2} + {d}^{2} } \ = sqrt{(15 + {a}^{2} ) + (49 - {a}^{2} )} \ = sqrt{15 + 49 + {a}^{2} - {a}^{2} } \ = sqrt{64} \ = 8 : cm$

JAWABAN : D

Gambar Jawaban