Question

The radius of a circle whose circumference is equal to the sum of the circumferences of
the two circles of diameters 36 cm and 20 cm is

a 1.56 cm b 2.42 cm c 3. 28 cm d 4.16 cm​

Answer 1

Step-by-step explanation:

$r1 = \frac{d1}{2} \\ = > r1 = \frac{36}{2} \\ = > r1 = 18cm \\ r2 = \frac{d2}{2} \\ r2 = \frac{20}{2} \\ \: \: \: \: \: \: = 10cm \\ \\ radius \: of \: the \: circle \: \: is \: r \: which \: is \: \\ to \: be \: find \\ \\ 2\pi \times r = 2\pi \times r1 \: + 2\pi \times r2 \\ r = r1 + r2 \\ = > r = 18 + 10 \\ = > r = 28 \: cm$