tolong dijawab no31-35 yang benar dengan caranya ya!

31. K = s1 + s2 + s3
36 = 10 + 2 s
2s = 36 - 10
2s = 26
s = 13 cm.
Karena segitiga sama kaki, maka ada 2 sisinya yang sama panjang yaitu 13 cm.
t = √13² - (a:2)²
t = √169 - (10:2)²
t = √169 - 5² = √169 - 25 = √144
t = 12 cm
➡L = a × t/2
➡L = 10 × 12/2
➡L = 10 × 6
➡L = 60 cm² (A)

32. K = 2(a + b)
54 = 2(a + 17)
54 = 2a + 34
2a = 54 - 34
2a = 20
a = AB = 10 cm
➡OB = √AB² - OA² = √10² - 6²
➡OB = √100 - 36 = √64
➡OB = 8
➡d1 = 2 × OB = 2 × 8
➡d1 = 16 cm
OC = √BC² - OB² = √17² - 8²
OC = √289 - 64 = √225
OC = 15 cm
d2 = OA + OC = 6 + 15
d2 = 21 cm
➡L = d1 × d2 / 2
➡L = 16 × 21 / 2
➡L = 8 × 21
➡L = 168 cm² (A)

33. PT = PR - RT
PT = 25 - 16
PT = 9 cm
• ST = SQ : 2
• ST = 24 : 2
• ST = 12 cm
PS = √PT² + ST² = √9² + 12 ²
PS = √81 + 144 = √225
PS = a = 15 cm
• RS = √RT² + ST² = √16² + 12²
• RS = √256 + 144 = √400
• RS = b = 20 cm
K = 2(a + b)
K = 2(15 + 20) = 2(35)
K = 70 cm (C)

34. QS = √PQ² - PS²
QS = √26² - 24²
QS = √676 - 576 = √100
QS = 10 cm
• QR = √QS² - RS²
• QR = √10² - 6²
• QR = √100 - 36 = √64
• QR = 8 cm
L. Bangun = LΔ.PQS + LΔ.QRS
L. Bangun = (a × t / 2) + (a × t / 2)
L. Bangun = (24 × 10 / 2) + (6 × 8 / 2)
L. Bangun = 120 cm² + 24 cm²
L. Bangun = 144 cm² (B)

35. 30° (A),caranya ada di gambar