Penjelasan dengan langkah-langkah:

1) D

9² + 18² > 20²

81 + 324 > 400

405 > 400 → ∆ lancip

2) B

9, 12, 6 → bukan triple phytagoras

karena 6² + 9² ≠ 12²

3) D

r = 15 cm

d = 30 cm

AB = 18,84 cm

<AOB = 360° x 18,84

30 x 3,14

= 12 x 6

= 72°

4) B

OP = OQ = 15 cm

OR = 9 cm

PQ = 2 x √(15²–9²)

PQ = 2 x √(225–81)

PQ = 2 x √144

PQ = 2 x 12

PQ = 24 cm

5) C

d = √(15²+8²)

d = √(225+64)

d = √289

d = 17 cm

6) A

CD = 150° x 45 cm

75°

CD = 2 x 45

CD = 90 cm

7) A

ABD = 90° – 67°

ABD = 23°

8) A

atas dan alas :

1 dan 6

2 dan 4

3 dan 5

9) A

PgsL = √(26² – [12–2]²)

PgsL = √(676–100)

PgsL = √576

PgsL = 24 cm

10) C

j = √(20² + (9+6)²)

j = √(400+225)

j = √625

j = 25 cm

11) B

t∆ = √(12²+[10/2]²)

t∆ = √(144+25)

t∆ = √169

t∆ = 13 cm

Luas sisi tegak = 2at∆

= 2 x 10 x 13

= 260 cm²