Given the circle A
CD is tangent to the circle and AD is a radius of the circle
So, CD ⊥ AD
So, the measure of angle ADC = 90
So, the triangle ADC is a right angle triangle
AC is the hypotenuse = AB + BC = 3.30 + 2.80 = 6.10
And AD = AB = the radius of the circle = 3.30
We will use the Pythagorean theorem to find CD
So,
So, the answer will be CD = 5.13