Tolong dibantu ya...

AB² = BD x BC
6² = BD X (BD + 5)
bd² + 5bd -36 = 0
(bd - 4)(bd + 9) = 0
ambil yg positif
maka bd = 4

BC = BD + DC = 5 + 4 = 9
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AD² = BD x CD
AD² = 5 x 4
AD = √20 = 2√5
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Luas ADC = 1/2 . AD . DC
L = 1/2 . 2√5 . 5
L = 5√5 satuan luas