Question

Calculate the degree of the angles in the triangles below.

Answer 1

the sum of the internal angles of a triangle is equal to 180, then

`\begin{gathered} 2x+7+5x+12=180 \\ 7x+19=180 \\ 7x+19-19=180-19 \\ 7x=161 \\ (7x)/(7)=(161)/(7) \\ x=23 \end{gathered}`

so

answer:

angle 1 = 2x + 7 = 2(23) + 7 = 46 + 7 = 53°

angle 2 = 5x = 5(23) = 115°

angle 3 = 12°