Answer:
1 - G;
2 - R;
3 - E;
4 - D;
5 - T;
6 - J;
7 - O;
8 - B;
Explanation:
The formula for calculating the sum of interior angles is ( n − 2 ) * 180 ∘ where n is the number of sides.
1) (4 - 2) * 180 = 360 therefore X + 100 + 118 + 53 = 360 => X = 360 - 100 - 118 - 53 = 89 => X = 89
2) (5 - 2) * 180 = 540 => 90 + 90 + X + 128 + X = 540 => 2*X = 540 - 90 - 90 - 128 = 232 => X = 116
3) (6 - 2) * 180 = 720 => 101 + 126 + X + 96 + 147 + 135 = 720 => X = 720 - 101 - 126 - 96 - 147 - 135 = 115 => X = 115
4) (9 - 2) * 180 = 7 * 180, since all angles are equal the answer is 7 * 180 / 9 = 7 * 20 = 140 => X = 140
5) (5 - 2) * 180 = 540 => 90 + 131 + 102 + X + 145 = 540 => X = 540 - 90 - 131 - 102 - 145 = 72 => X = 72
6) Since the sum of the linear pair angles equal 180, X = 180 - 70 = 110 => X = 110
7) (4 - 2) * 180 = 360; Linear pair angle for 73 is 180 - 73 = 107, that means X + 102 + 39 + 107 = 360 => X = 360 - 102 - 39 - 107 = 112 => X = 112
8) (5 - 2) * 180 = 540; Linear pair angle for 84 is 180 - 84 = 96; Linear pair angle for 79 is 180 - 79 = 101; Linear pair angle for 34 is 180 - 34 = 146; so X + 90 + 96 + 101 + 146 = 540 => X = 540 - 90 - 96 - 101 - 146 = 107 => X = 107