hitulang la luas lingkaran a r=20cm b r=35cm c r=30cm

[tex]a. \: l \: = \pi \times {r}^{2} \\ = 3.14 \times {20}^{2} \\ = 3.14 \times 400 \\ = 1256 \: {cm}^{2} \\ \\ b. \: l \: = \pi \times {r}^{2} \\ = \frac{22}{7} \times {35}^{2} \\ \\ = \frac{22}{7} \times 1225 \\ \\ = 22 \times 175 \\ \\ = 3850 \: {cm}^{2} \\ \\ c. \: l \: = \pi \times {r}^{2} \\ \\ = 3.14 \times {30}^{2} \\ \\ = 3.14 \times 900 \\ \\ = 2826 \: {cm}^{2} [/tex]