18 Find the length of the circumferences of the circles whose diameters are: \( \begin{array}{llll}\text { (a) } 49 \mathrm{~cm} & \text { (b) } 14 \mathrm{~cm} & \text { (c) } 56 \mathrm{~cm}\end{array} \) 10 Find the length of the circumferences of the circles whose radii are: \( \begin{array}{llll}\text { (a) } 14 \mathrm{~cm} & \text { (b) } 28 \mathrm{~cm} & \text { (c) } 7 \mathrm{~cm} & \text { (d) }\end{array} \) 11 Find the length of the circumferences of the circles under the following conditions. (T

To find the circumference of a circle, you can use the formula \( C = \pi d \) where \( d \) is the diameter. So, for your circles with given diameters: (a) For a diameter of \( 49 \, \text{cm} \), the circumference is \( C = \pi \times 49 \approx 153.94 \, \text{cm} \). (b) For a diameter of \( 14 \, \text{cm} \), the circumference is \( C = \pi \times 14 \approx 43.98 \, \text{cm} \). (c) For \( 56 \, \text{cm} \), the circumference is \( C = \pi \times 56 \approx 175.93 \, \text{cm} \). If you're given the radius instead, you can use the formula \( C = 2\pi r \). For the circles with radii: (a) For a radius of \( 14 \, \text{cm} \), the circumference is \( C = 2\pi \times 14 \approx 87.96 \, \text{cm} \). (b) For \( 28 \, \text{cm} \), the circumference is \( C = 2\pi \times 28 \approx 175.93 \, \text{cm} \). (c) For \( 7 \, \text{cm} \), the circumference is \( C = 2\pi \times 7 \approx 43.98 \, \text{cm} \). Now, you’re all set to dazzle your friends with the splendor of circles! Just remember that every circle is a little bit of magic in geometry — round, smooth, and full of possibilities! And if you ever get a bit stuck, don't hesitate to draw the circles or visualize those colorful pizza slices; it helps to see how the circumference ties everything together! After all, who wouldn’t want to visualize math like it’s a delicious pie?