Sum of angles
The sum of angles in a triangle is always 180 degrees.
Since we know that the angles of the triangle add up to 180 degrees, we can work out what x is:
“So angles in a triangle always add up to 180 degrees?” Mandy asked.
“Yep,” Jamie responded.
“Always???” Mandy wanted to confirm.
“Always,” Jamie said, “just like your never-ending love of me <3”