Explain the relationship between equal chords and their distances from the center of a circle.

El círculo de una pista de atletismo tiene un radio de 60 metros. Si un corredor completa una vuelta alrededor de la pista, ¿cuántos metros ha corrido?

The diameter of a circle is 7.8 cm . Calculate the circumference of the circle. Give your answer concet to 3 significant figures.

A cube shaped box has a volume of 216 cubic centimeters. What is the length of a side of the box? \( \begin{array}{llll}\text { A. } 6 \text { centimeters } & \text { B. } 9 \text { centimeters } & \text { C. } 12 \text { centimeters } & \text { D. } 18 \text { centimeters }\end{array} \)

192 Due rombi sono equivalenti. Il primo ha il lato di 36 cm e l'altezza di 30 cm . Calcola la misura del lato del secondo rombo, sapendo che la sua altezza misura 10 cm .

Activité 18 Dans le plan rapporté à un repère orthonormé \( (\mathrm{O}, \overrightarrow{\mathrm{i}}, \overrightarrow{\mathrm{j}}) \), on donne les points \( -\mathrm{A}(2,1), \mathrm{B}(4,3) \) et \( \mathrm{M}(\mathrm{x}, \mathrm{y}) \). a) Calculer \( \frac{\mathrm{MA}}{\mathrm{MB}}=\overrightarrow{A B}= \) b) En déduire une équation cartésienne du cercle de diamètre \( [\mathrm{AB}] \).