what is the measure of m<1 will ensure that the rail is parallel to the bottom of the staircase?
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You can observe that angle 1 and angle with 47° are inside a parallelogram.
Consider that the sum of the internal angles of a parallelogram is 360°.
Moreover, consider that the angle at the top right of the parallogram is congruent with the angle of 47°, then, such an angle is if 47°.
Consider that angle down right side is congruent with angle 1, then, they have the same measure.
You can write the previous situation in the following equation:
47 + 47 + ∠1 + ∠1 = 360 simplify like terms
94 + 2∠1 = 360 subtract both sides by 94
2∠1 = 360 - 94
2∠1 = 266 divide by 2 both sides
∠1 = 266/2
∠1 = 133
Hence, the measure of angle 1 is m∠1 = 133°