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GSE Geometry
1 – Angles and Transformations
1.1 – Notes
Name: ________________________________________________ Date: _______________________
Angles
TYPE OF ANGLE
MEASUREMENT
SKETCH
ACUTE
RIGHT
OBTUSE
STRAIGHT
What is an angle? An angles consists of two different rays that have the same initial
point.
Congruent Angles: Two or more angles with the same measure.
Adjacent Angles: Two angles with a common vertex and side, but no common interior
points.
1. Angle Bisector: A ray (or line or segment) that divides an
angle into two congruent angles.
Example:
2. Vertical Angles: Two angles are vertical angles if their sides
form two pairs of opposite rays.
**VERTICAL ANGLES ARE ____________________
Example:
3. Linear Pairs: Two adjacent angles are linear pairs if their
non-common sides are opposite rays.
**LINEAR PAIRS ARE _________________________
Example:
GSE Geometry
1 – Angles and Transformations
1.1 – Notes
Practice:
1. Can two supplementary angles both be obtuse angles? Acute? Right?
BE is an angle bisector.
2. If mABE = 40, then mEBC = ____________.
3. If mABC = 4x-12 & mABE = 24°, then x = ____________.
.
4. 1 and 2 are complementary. Solve for x and the measure of both angles.
1 = 5x + 2
2 = 2x + 4
5. 1 and 2 are supplementary. Solve for x and the measure of both angles.
1 = 12x + 4
2 = 9x + 8
6.
One of two complementary angles is 16 degrees less than its complement. Find the
measure of both angles.
7.
One of two supplementary angles is 123° less than twice its supplement. Find the
measure of both angles.
8.
x = ____________
9.
y = ____________
10. Given: AB intersects CD at E
Prove: 1  2
D
A
1
E
C
2
3
B
STATEMENT
REASON