Ineed to find the equation, the x value and angles abc and gfh.

Angles ABC and GFH are a pair of alternate exterior angles of these two parallel lines cut by a transversal. This means they are congruent (properties of two parallel lines cut by a transversal).

Set them equal to each other to find x.

10x + 20 = 12x

Subtract 10x from both sides.

20 = 2x

Divide both sides by 2.

10 = x

To find the measures of angles ABC and GFH, substitute 10 for x in their angle values accordingly and solve.

10x + 20

10(10) + 20

100 + 20

120

12x

12(10)

120

x = 10; m∠ABC = 120; m∠GFH = 120

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