Chapter 9, Problem 6CR

To determine

To find:The value of angle BFC .

Answer to Problem 6CR

The value of $\angle BFC={130}^0$

Explanation of Solution

Given information:The following information has been given

  $\angle ABC={60}^0$

  $\angle ACB={70}^0$

  $\angle AEB=\angle BEC={90}^0$

  $\angle CDB=\angle CDA={90}^0$

Calculation:We know that in triangle BCD ,

  $\angle ABC={60}^0$ ,

  $\angle CDB={90}^0$ ,

Hence, we get

  $\angle BCD={30}^0$

Now, as $\angle BCD={30}^0$ , we can say that

  $\angle ECF={40}^0$

Now, in triangle EFC, we know that

  $\angle BFC=\angle ECF+\angle CFE$

Thus, substituting the values, we get

  $\angle BFC={40}^0+{90}^0={130}^0$