Name ________________________ Period ____ Date ___________
STEPS TO WRITING & SOLVING GEOMETRY EQUATIONS
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Identify x, “Let x = … “
Write an expression for each angle
Write the necessary formula
Complete F.S.A. (Formula, Substitute, Answer)
Substitute the value for x back in to find each angle measure
Check your work by using F.S.A.
TYPES OF FORMULAS TO USE:
Congruent Angles -
FORMULA: < 1 = < 2
Vertical Angles –
Opposite angles, they form an “x”
Example: <S and <W
Corresponding Angles –
On the same side of the transversal, in the same position
Example: <P and <T
Alternate Interior Angles –
Inside the parallel lines, on opposite sides of the transversal
Example: <Q and <T
Alternate Exterior Angles –
Outside the parallel lines, on opposite sides of the transversal
Example: <P and <U
Supplementary Angles -
FORMULA: <1 + <2 = 180˚
Two angles whose measures add to 180˚
Example: <P and <R
Complementary Angles -
FORMULA: <1 + <2 = 90˚
Two angles whose measures add to 90 ˚
Triangle Sum Theorem -
FORMULA: <1 + <2 + <3 = 180˚
The sum of all three angles of any triangle add to 180˚