Question

Can someone solve then explain the process of solving this?

Answer 1

`{ \qquad\qquad\huge\underline{{\sf Answer}}}`

By angle sum property of a triangle :

`\qquad \sf  \dashrightarrow \: x + 69 + x + 55 + 78= 180 \degree`

`\qquad \sf  \dashrightarrow \: 2x +202= 180`

`\qquad \sf  \dashrightarrow \: 2x = 180 - 202`

`\qquad \sf  \dashrightarrow \: 2x = - 22`

`\qquad \sf  \dashrightarrow \: x = - 11`

So, value of x is -11, now plug the value of x in angle A to get its measure~

`\qquad \sf  \dashrightarrow \: x + 69 = - 11 + 69 = 58 \degree`

Hence, Angle A = 58°