Chapter 10.8, Problem 13PSB

To determine

To Find : Radius of circle.

Answer to Problem 13PSB

  $2.5$

Explanation of Solution

Given Information: $\begin{array}{l}\text{1)}\text{CD is tangent at D}\\ \text{2)}\text{CD = 6}\\ \text{3)}\text{BC = 4}\end{array}$

Formula Used: The tangent at a point on a circle is at right angles to this radius.

  

Calculation: $\begin{array}{l}{\text{OC}}^{\text{2}}=O{D}^2+C{D}^2\\ $ {(4+x)}^2=x^2+62$x^2+8x+16=x^2+36\\ 8x=20\\ x=20/8\\ x=2.5\end{array}$