A triangle has one angle that measures 19 degrees, one angle that measures 118 degrees, and one angle that measures 43 degrees. What kind of triangle is it?

A. right triangle

B. obtuse triangle

C. acute triangle

D. equilateral triangle

B. obtuse triangle

Step-by-step explanation:

Obtuse triangles are triangles with one obtuse angle and two acute angles. Define obtuse angles as angles over 90 degrees and acute angles as angles less than 90 degrees.

In this triangle:

118 degrees - obtuse angle

19 degrees - acute angle

43 degrees - acute angle

Thus, this triangle is an obtuse triangle.

B. (2, 7)

Step-by-step explanation:

(1)  5x + 3y = 31

(2) 2x + 3y = 25     Subtract (2) from (1)

            3x = 6        Divide each side by 3

              x = 2        Substitute in (2)

     4 + 3y = 25       Subtract 4 from each side

           3y = 21        Divide each side by 3

             y = 7

The solution is (2, 7).

Check:

(1)   5×2 + 3×7 = 31

          10 + 21 = 31

                 31 = 31

(2) 2×2 + 3×7 = 25

           4 + 21 = 25

                25 = 25