Page 886 - Algebra 1

Vertical Angles
Skills Bank Lesson 25
When two lines intersect, the nonadjacent angles are called vertical angles. Vertical angles always have the same measure, so they are congruent angles.
Finding the Measure of Vertical Angles
Find m∠WVY, m∠YVZ, and m∠ZVX, where m∠XVW = 70°.
Example
1
WY V
a.
SOLUTION
XZ
m∠XVW + m∠WVY = 70° + m∠WVY =
180°
∠XVW and ∠WVY are supplementary. Substitute.
Vertical angles have the same measure.
Vertical angles have the same measure.
b. Find m∠ABQ, m∠ABC, and m∠CBR. AC
B 100°
QR
d. Find m∠BAC, m∠DAE, and m∠EAB, where m∠CAD = 140°.
BC IHA
ED
180° m∠WVY = 110°
m∠YVZ = m∠YVZ = 70°
m∠ZVX = m∠ZVX = 110°
m∠XVW m∠WVY
Skills Bank Practice
a. Name the two pairs of vertical angles. BC
E
A
D
c. Find m∠EFG, m∠GFH, and m∠HFI, where m∠EFI = 20°.
EG F
Skills Bank 871
SKILLS BANK