Question

QUIZZZ

Soal tertera

Opsi jawaban :
a) 4√3
b) 3√5
c) 2√3
d) 2
e) 3√3
​

Answer 1

A. 4√3

Penjelasan dengan langkah-langkah:

diketahui ∆ABC didalam lingkaran O

<BAC = 60°

AB= 7

AC = 5

BC² = AB² + AC² - 2(AB×AC)cos 60

= 49 + 25 - 2(5×7)½

= 74 - 35

= 39

BC = √39

Luas ∆ABC

= ½AB×AC×sin 60

= (35/4)√3

Jari - jari Lingkaran

= (AB×AC×BC) : 4(Luas ∆ABC)

= (5×7×√39) : 4(35/4)√3

= (35√39) : 35√3

= √39 / √3

= √13

AD = x

<CAD = 30 = sudut keliling dari <COD

<COD = 2× <CAD = 2(30) = 60°

Dinyatakan ∆COD sama sisi

AO = OD = CD = r = √13

Terbentuk ∆ADC

<CAD = 30

AC= 5

CD=√13

AD = x

CD/sin 30 = AC/sin <CDA

sin <CDA = AC(sin 30) / CD

= 5(½) /√13

= 0,6934

<CDA = arc sin 0.6934

= 43,9°

<ACD = 180 - (30+43,9)

= 180 - 73,9

= 106,1°

CD/sin 30 = x/sin 106,1°

x = CD(sin 106,1) : sin 30

= √13( 0,9608) : ½

= 6,9282

= 4√3