Answer:
100
Step-by-step explanation:
As stated, the interior angles formed by the sides of a hexagon have measures that sum to 720°.
To find the measure of angle A, we first need to find value of x:
110 + 120 + 130 + x-40 + x-60 + x-20 = 720 add like terms
3x + 240 = 720 subtract 240 from both sides
3x = 480 divide both sides by 3
x = 160 now replace x with 16 to find angle A
x-60 is 160 - 60 = 100
