Adjacent Angles Definition

​Adjacent angles are two angles are adjacent if they have a common side and a common vertex.

Adjacent angles are directly next to each other and do not overlap.

​Adjacent Angles-Illustrations

Adjacent Angles Properties/Facts

• They share the common vertex.

• They share the common arm.

• Adjacent angles do not overlap each other.

• Adjacent angles can be complementary or supplementary angles when they share the common vertex.

Adjacent Angles Example

a + 47 = 75

- 47 -47

a = 28

Check

28 + 47 = 75

Vertical Angles Definition

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Vertical angles opposite each other when two lines cross. They are always equal.

Vertical Angles Properties/Facts

Vertical angles are a pair of angles with the following two properties:

1) their sides are determined by the same lines;

2) they share a vertex but not a side. The vertical angle are congruent(equal shape and size).

Vertical Angles

Vertical Angles Illustrations

Vertical Angles

Vertical Angles Example Problem

​a = b

If a is equal to 35, which means

35 = b

then b is also equal to 35

b = 35

Check:

35 = 35 (the equation is balanced)