Answer:
X= 9
Explanation:
The angles in a triangle all add up to 180°
Hence we can form this equation :
63 + 7x + 6x = 180°
Subtracting 63 from both sides:
7x + 6x = 117°
Adding together to find the total X:
13x = 117°
Finally, diving by 13 on both sides:
X = 9