tolong ya para kawan kawan

17. 77 = ?/360 × 22/7 × 14 × 14
= ?/90 × 22 × 7
= ?/90 × 154
77/154 = ?/90
? = 1/2 × 90
= 45
18. pgsl = ✓17 × 17 - (10-2)(10-2
= ✓289 - 64
= ✓224 = 15 cm
19.pgsd = ✓13 × 13 - (8+4)(8+4
= ✓169 - 144
= ✓25 = 5cm