Chapter E, Problem 6.6EX

To determine

To find the longest side of $\Delta DEF$ .

Answer to Problem 6.6EX

Option (b) $\overline{EF}$ , is correct.

Explanation of Solution

Given information: In $\Delta DEF$ , $m\angle D=50$ , and an exterior angle with vertex F has measure 120 .

Options,

a. $\overline{DE}$

b. $\overline{EF}$

c. $\overline{DF}$

d. unknown

Calculation: The required solutions is obtained as,

Exterior $\angle F=120$

Interior $\angle F=180-120=60$

  $\angle E=180-50-60=70$

The opposite side is longest one.

Therefore, option (b) $\overline{EF}$ , is correct.