A triangle is shown with squares, 1,2 and 3 drawn on its side which measurements in units for the sides of the square show that the triangle is a right triangle

X equals 10, Y equals six, Z equals eight
X equals four, Y equals two, Z equals three
X equals nine, Y equals five, Z equals seven
X equals seven, Y equals three, Z equals four

The triangle that is a right triangle is:

X equals four, Y equals two, Z equals three. This triangle satisfies the Pythagorean theorem since 4^2 + 2^2 = 3^2, making it a right triangle.