Use a graph to find the length of DE if D(4, -3) and E(-5, -7) in pythagoras theorem.
we know that
Applying the Pythagorean Theorem
DE^2=DEx^2+DEy^2
DEx -----> is the distance in the x-coordinate
DEy -----> is the distance in the y-coordinate
DEx=(-5-4)=-9 ------> subtract the x-coordinates
DEy=(-7+3)=-4 -----> subtract the y-coordinates
substitute in the formula
DE^2=(-9)^2+(-4)^2
DE^2=97
![DE=\sqrt[]{97}\text{ units}](https://img.qammunity.org/2023/formulas/mathematics/college/k84f1g2fj18n1bmgg7hkss61auvpum7xiz.png)
c^2=a^2+b^2
c -----> is the distance DE
a ----> horizontal leg
b ----> vertical leg
we have
a=(-5-4)=-9 ------> subtract the x-coordinates
b=(-7+3)=-4 -----> subtract the y-coordinates
substitute
c^2=(-9)^2+(-4)^2
c^2=97
![c=\sqrt[]{97}\text{ units}](https://img.qammunity.org/2023/formulas/mathematics/college/k6gjaboaok3sosbiuh6tb2z7ud9r59w0oz.png)