Answer:
r = 8
Step-by-step explanation:
[tex]\frac{3.6}{3.15}[/tex] = [tex]\frac{r}{7}[/tex] ( cross- multiply )
3.15r = 3.6 × 7 = 25.2 ( divide both sides by 3.15 )
r = [tex]\frac{25.2}{3.15}[/tex] = 8
8