Answer:
![\widehat{DE}=70^(\circ)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/t3rj3hottwnnjmjiez9np4e1qnzglqcsg3.png)
Step-by-step explanation:
We have been given a circle. We are asked to find measure of minor arc DE.
We know that the circumference of circle is equal to 360 degrees. We can set an equation using our given information.
![\widehat{AB}+\widehat{BC}+\widehat{CD}+\widehat{DE}+\widehat{EF}+\widehat{FA}=360^(\circ)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/xugy8h8m0derz470yj8xpwiy8roahu58tq.png)
![20^(\circ)+30^(\circ)+40^(\circ)+\widehat{DE}+110^(\circ)+90^(\circ)=360^(\circ)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/wwvhxjxnchmob9aioroivvkfjyj3k94c1c.png)
![\widehat{DE}+290^(\circ)=360^(\circ)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/sn1zz7xrblhlfq1c0kkch2t0uiu8vfhb67.png)
![\widehat{DE}+290^(\circ)-290^(\circ)=360^(\circ)-290^(\circ)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/dyhuc4d4qav30jc9838as6b5mfje0x6ow0.png)
![\widehat{DE}=70^(\circ)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/t3rj3hottwnnjmjiez9np4e1qnzglqcsg3.png)
Therefore, measure of minor arc DE is 70 degrees.