Ray AB or AB An angle consists of two different rays with the same endpoint. Ray BA or BA The ray symbol doesn't indicate a direction. The endpoint is always the first point used when naming a ray. The rays that are used to make the angle. The endpoint of the rays that make the angle. The number of degrees (or radians) that separate the two sides of an angle. An angle whose measure is between 0° and 90° An angle whose measure is 90°. An angle whose measure is greater than 90° and less than 180° An angle whose measure is 180° Angles with the same measure. A ray that divides an angle into two congruent angles.

∠ABC ∠CBA ∠CBD ∠DBC vertex ∠ABD ∠DBA

180° ∠AOB the absolute value difference

outer You always start counting from 0. 65° outer 65° an acute inner 115° inner 115° an obtuse 180° a straight 90° a right

∠FGJ or ∠JGF, ∠JGH or ∠HGJ and ∠FGH or ∠HGF The x and y axis form a right angle because horizontal and vertical lines are perpendicular.

RSP PST RSP PST

GFH HFJ 155° 4x + 4 4x - 1 155 8x + 3 152 8x 3 19 8 19 4x + 4 4(19) + 4 80° 4x - 1 4(19) - 1 75° 80° 75°

∠N ∠M ∠N m∠N 120°

∠XWY ∠YWZ ∠XWY ∠YWZ m∠XWY m∠YWZ m∠XWY m∠YWZ 29 29° 58°

∠B ≅ ∠D and ∠A ≅ ∠ C m∠D = 135° ∠LKN = ∠LKM + MKN ∠LKN = 78° + 78° ∠LKN = 156°