Perhatikan gambar!tentukan nilai 1. nilai a…2. nilai a & b​

I.

PK = 6 cm

KQ = 4 cm

PQ = 6 cm + 4 cm = 10 cm

PJ = a cm

JR = 3 cm

PR = a + 3 cm

a = ?

PK : PQ = PJ : PR

6 : 10 = a : (a + 3)

6 × (a + 3) = a × 10

6a + 18 = 10a

18 = 10a – 6a

18 = 4a

a = 18 ÷ 4

a = 4,5 cm

II.

PK = 6 cm

KQ = 4 cm

PQ = 6 cm + 4 cm = 10 cm

PJ = a cm

JR = 2 cm

PR = a + 2 cm

JK = b cm

QR = 10 cm

a = ?

b = ?

PK : PQ = PJ : PR

6 : 10 = a : (a + 2)

6 × (a + 2) = a × 10

6a + 12 = 10a

12 = 10a – 6a

12 = 4a

a = 12 ÷ 4

a = 3 cm

PK : PQ = JK : QR

6 : 10 = b : 10

6 × 10 = b × 10

60 = 10b

b = 60 ÷ 10

b = 6 cm