In the given figure, two identical circles of radius 4 cm touch each other. A and B are the centres of the two circles. If RQ is a tangent to the circle, then what is the length (in cm) of RQ?

Answer: Option C

n² = 8 × 16
n² = 128
n = 8$$\sqrt{2}$$

b = (8$$\sqrt{2}$$ + a)
a² + (16)² = b²
a² + (16)² = (8$$\sqrt{2}$$ + a)²
a² + 256 = 128 + a² + 16$$\sqrt{2}$$ a
128 = 16$$\sqrt{2}$$ a
a = $$\frac{8}{\sqrt{2}}$$
a = 4$$\sqrt{2}$$