Which equation is the equation of the line, in point-slope form, that has a slope of -4 and passes through the point (7, 1)? A) y-7 = 4(x - 1)
B)y-1= -4(x + 7)
C)y-7 = -4(x - 1)
D) y-1= -4(x - 7)

Given: abcd is a square. prove: ac ? bd. we are given that abcd is a square. if we consider triangle aeb and triangle aed, we see that side is congruent to side ad because sides of a square are congruent. we know that side ae is congruent to side ae by using the . finally, we know that side de is congruent to side because the diagonals of a square bisect each other. therefore, triangle aeb is congruent to triangle aed by congruency. we see that angle aed and angle aeb are a linear pair, and congruent by cpctc. thus, the measure of these angles will be 90°, and diagonal ac is perpendicular to diagonal bd by the .