Bantu jawab soal yg ada di gambar

Ltembereng = Ljuring - Lsegitiga

Ljuring = α · Llingkaran / 360
Ljuring = α · π · r² / 360
Ljuring = 90 · 22/7 · 21 · 21 / 360
Ljuring = 22 · 3 · 21 / 4
Ljuring = 11 · 3 · 21 / 2
Ljuring = 346.5cm²

Lsegitiga = a · t / 2
Lsegitiga = 21 · 21 / 2
Lsegitiga = 441 / 2
Lsegitiga = 220.5cm²

Ltembereng = 346.5cm² - 220.5cm²
Ltembereng = 126cm² (A)

Luas tembereng=L.juring-L.Δ
L juring=90°/360°×L.lingkaran
L 1/4 lingkaran=1/4×π×r×r
=1/4×22×7×21×21
=692cm²
L juring=90/360×692
=173cm
luasΔ=a×t/2=21×21/2
=22cm²
Luas tembereng=173-22=151cm