tolong kaa bsk dikumpulkan

1. Keliling = 2(p+l) - 1/4×2phi r - 1/2 × phi d
= 2(21+14) - 1/2×22/7×7 - 1/2 × 22/7×7
= 42+28 - 11-11
= 48 cm.

Luas = (P×l) - phi×r² - phi×r²
= 294 - 154 - 38,5
= 140 - 38,5 = 101,5 cm²

2. 45/360 × phi × r²
= 1/8 × 22/7 × 7m×7m
= 1/8 × 22 × 7
= 11/4 × 7 = 19,25 m²