Question

1_Dari gmbr 1,besar sudut Q adalah...
a.46
b.56
c.84
d.94

2_Perhatikan gmbr 2,luas persegi panjang adalah...
a.94cm²
b.110
c.120
d.145

3_Pd gmbr 3,pajng sisi AB adalah..
a.12cm
b.10
c.9
d.8

4_Perhatikan gmbr 4,jika keliling segitiga ABC adalah 30 cm,maka panjang sisi AC adalah...
a.11cm²
b.9
c.8
d.6

5_Perhatikan gmbr 5,Luas segitiga PQR adalah...
a.180cm²
b.120
c.90
d.80

Answer 1

Nomor 1.
<P + <Q + <R = 180°
2x + 3x + 40° = 180°
5x = 180° - 40°
5x = 140°
x = 28°
Sehingga,
<Q = 3x
<Q = 3(28°)
<Q = 84° [C]

Nomor 2.
Pengan phytagoras:
AB = √AC²-BC²
AB = √17²-8²
AB = √289-64 = √225 = 15
Sehingga,
L = AB x BC
L = 15 x 8
L = 120 cm² [C]

Nomor 3.
Jajargenjang, AB = CD
3x + 2 = x + 6
3x - x = 6 - 2
     2x = 4
       x = 2
Sehingga,
AB = 3x + 2
AB = 3(2)+2
AB = 6+2
AB = 8 cm [D]

Nomor 4.
K = 30
Maka,
AB + AC + BC = 30
x + (x+7) + (2x+7) = 30
4x + 14 = 30
4x = 30 - 14
4x = 16
x = 4
Maka,
AC = x+7
AC = 4+7
AC = 11 cm [A]

Nomor 5.
Phytagoras:
QS = √QR²-RS²
QS = √17²-15² = √289-225
QS = √64
QS = 8 cm

Sehingga, luasnya:
= 1/2 PS.SR - 1/2 QS.SR
= 1/2 SR (PS-QS)
= 1/2 SR (PQ+QS-QS)
= 1/2 SR.PQ
= 1/2 x 15 x 12
= 90 cm² [C]