Which statement explains how you could use coordinate geometry to prove that quadrilateral ABCD is a square

Mathematics

1 answer:

mixer [17]2 years ago

3 0

Answer:

Prove that all sides are congruent and that the slopes of consecutive sides are opposite reciprocals. Step-by-step explanation: In order to two segmets to be perpendicular, the slope of both lines must be opposite and reciprocals, having a 90° interception and forming a square.

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Can someone help me solve this?

julsineya [31]

Answer:

im sorry i cant see that

Step-by-step explanation:

8 0

3 years ago

A line joins the point

Harrizon [31]

Intersection of the first two lines:

$\begin{cases}5x - 2y + 3 = 0\\4x - 3y + 1 = 0\end{cases}$

Multiply the first equation by 4 and the second by 5:

$\begin{cases}20x - 8y + 12 = 0\\20x - 15y + 5 = 0\end{cases}$

Subtract the two equations:

$(20x - 8y + 12)-(20x - 15y + 5)=0 \iff 7y+7=0 \iff y=-1$

Plug this value for y in one of the equation, for example the first:

$5x - 2\cdot (-1) + 3 = 0\iff 5x+5=0 \iff x=-1$

So, the first point of intersection is $(-1,-1)$

We can find the intersection of the other two lines in the same way: we start with

$\begin{cases}x=y\\x=3y+4\end{cases}$

Use the fact that x and y are the same to rewrite the second equation as

$x=3x+4 \iff 2x=-4 \iff x=-2$

And since x and y are the same, the second point is $(-2, -2)$

So, we're looking for a line passing through $(-1,-1)$ and $(-2, -2)$ . We may use the formula to find the equation of a line knowing two of its points, but in this case it is very clear that both points have the same coordinates, so the line must be $y=x$