Tolong jawab no 21 pakai cara yah!

P.sisi = 10 cm
r = 5 cm
Alas = 10cm
T =
[tex] \sqrt{100 - 25 } = \sqrt{75} = 8.65 \: cm[/tex]

L.lingkaran =
[tex]\pi \times r {}^{2} [/tex]
[tex]3.14 \times 5 \times 5 = \\ 3.14 \times 25 = 78.5 \: cm {}^{2} [/tex]
L.Segitiga
= 1/2×Alas×tinggi
= 1/2×10×8.65
= 1/2×86.5
[tex] = 43.25cm {}^{2} [/tex]
L. yang diarsir
=L.lingkaran - L.segitiga
=78.5 - 43.25
A
[tex] = 35.25cm {}^{2} [/tex]

Semoga membantu :3