Lines BC and EF have the opposite and reciprocal slopes given that triangle ABC has been rotated 90° to create triangle DEF. This can be obtained by finding the slopes of each line and comparing them.
m = rise/run = Δy/Δx = (y₂ - y₁)/(x₂ -x₁)
where m is the slope of the triangle, (x₁, y₁) and (x₂, y₂) are the endpoints of the lines. (y₂ - y₁) is the rise and (x₂ -x₁) is the run.
m = rise/run = Δy/Δx = tan(∅)
where ∅ is the angle between Δx(run) and hypotenuse
From the question we can calculate the slope using the formula of slope,
(4, 5) and (1, 2) are the endpoints of the line BC
Slope of the line BC,
m₁ = (y₂ - y₁)/(x₂ -x₁) = (2 - 5)/(1 - 4)
m₁ = -3/-3
m₁ = 1
(2, -1) and (5, -4) are the endpoints of the line EF
Slope of the line EF,
m₂ = (y₂ - y₁)/(x₂ -x₁) = (-4 - (-1))/(5 - 2)
m₂ = -3/3
m₂ = - 1
Slope of the line BC is 1 and slope of line EF is - 1, and 1 and - 1 are opposite and reciprocal.
Since lines BC and EF have the opposite and reciprocal slopes given that triangle ABC has been rotated 90° to create triangle DEF.
Learn more about slopes here:
brainly.com/question/17870676
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