Atriangle has sides with lengths of 10 yards, 13 yards, and 18 yards. is it a right triangle?

No

Step-by-step explanation:

By the Pythagorean Theorem, if a triangle is a right triangle then it must have the property that a^2 + b^2 = c^2, where c is the longest side, and a and b are the two shorter sides. In the triangle, it does not satisfy this, so it is not a right triangle.

in the attachment.   i didn't see your choices.   the word which means there is choices.

step-by-step explanation:

(x,y)

x tells you how much left or right you go from the origin

y tells you how much down or up you go from the origin

so for example (-3,2), you go left 3 and up twice. i denoted which of the ordered pairs is which in my graph.