Tolong bantu ya bersama caranya....plis....besok harus selesai

no.5
cos a= 4/5 artinya AB=4 dan AC=5.
maka sisi BC=
[tex] {bc}^{2} = {ac}^{2} - {ab}^{2} \\ \: \: \: \: \: \: = {5}^{2} - {4}^{2} \\ \: \: \: \: \: \: = 25 - 16 \\ \: \: \: \: \: = 9 \\ \sqrt{ {bc}^{2} } = \sqrt{9} \\ bc = 3 \\ [/tex]

AD=4-3
=1
jadi panjang AD= 1


[tex] {cd}^{2} = {bd}^{2} + {bc}^{2} \\ \: \: \: \: \: = {3}^{2} + {3}^{2} \\ \: \: \: \: = 9 + 9 \\ \: \: \: \: \: = 18 \\ \sqrt{ {cd}^{2} } = \sqrt{18 } \\ cd = 3 \sqrt{2} \\ jadi \: panjang \: cd \: = 3 \sqrt{2} [/tex]