Two right triangles are similar if an acute angle of one triangle is congruent to an acute angle of the other triangle. a. true b. false

  True

One angle of a right triangle  = 90°
Let x =  the acute angle of one angle.
Let y =  the angle of the other angle.

Because the sum of angles in a triangle is 180°,
x + y + 90 = 180
x + y = 90
y = 90 - x

Therefore the angles for each of the two triangles are
x, 90° - x, 90°.

The two triangles are therefore similar because of AAA (Angle, Angle, Angle).