tolong dijawab ya soal no 1-2 bagi yang tau caranya tolong di isi ya

Trigonometri

cot B = cos b/sin B
sec B = 1/cos B

(1 + cot² B)/(cot B . sec² B) =
= (1 +  cos² B/sin B) / ( cos B/sin B . 1/cos² B) =
= (1+ cos² B/sin B) / (1/(sin B cos B)  ...kalikan sin²B/sin²B
= sin² B(1 + cos²B/sinB) / sin² B(1/(sin B cos B)
= (sin² B + cos² B) / (sin B/cos B)
= 1/ (tan B)
= cot B

2. ΔABC siku siku di A

AB = x+1
AC = x+ 8
BC = 2x+3

Luas Δ ABC = 60
1/2 (AB)(AC) = 60
AB. AC = 60
(x+8)(x+1) = 60
x² - 9x + 8 - 60 = 0
x² - 9x - 52 =0
(x - 13)(x + 4) = 0
x = 13  atau x  = - 4 (tidak memenuhi)

Keliling = AB +AC + BC
K = x+8 + x + 1 + 2x+ 3
K = 4x + 12
K = 4(13) + 12
K = 52 + 12
K = 64 cm