Concept:Sine is negative in the third and fourth quadrants.Explanation:Given sinx=−sin70∘, where 0∘<x<360∘.Since sin70∘ is positive, x must be in the third or fourth quadrant.In the third quadrant, x=180∘+70∘=250∘.Check: sin250∘=−sin(250∘−180∘)=−sin70∘.In the fourth quadrant, x=360∘−70∘=290∘.Check: sin290∘=−sin(360∘−290∘)=−sin70∘.Thus the two possible values are 250∘ and 290∘.Answer:x=250∘,290∘ (Option D).