A company makes two types of electronic devices: laptops and tablets. Its business plan says that it must produce from 70 to 130 laptops, and from 50 to 110 tablets, per day. The total number of devices it must make per day according to the plan ranges from 150 to 220. Given that x is the number of laptops made per day, and y is the number of tablets made, what are the daily constraints that the plan places on the company?

1. 180°. the sum of the interior angles of a triangle is 180°, for the equilateral triangle that it has three equals side is 60°+60°+60°=180°.

2. 60°. each interior angle of a equilateral triangle is 60°

3. 120°. the measure of ∠m is 120°, the sum of the angles ∠m and ∠n is equal to 180°. so, in order to find the measure of ∠m, we have ∠m+∠n=180° > ∠m=180°-∠n > ∠m=180°-60°=120°.

4. 360°. the sum of the exterior angles of an equilateral triangle is ∠m+∠r+∠x=120°+120°+120°=360°. the exterior angles of any triangle always add 360°.

answer: i think it is c