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## Algebra basics

## Equation practice with vertical angles

- Equation practice with complementary angles
- Equation practice with supplementary angles
- Your answer should be
- an integer, like 6 6 6 6
- a simplified proper fraction, like 3 / 5 3/5 3 / 5 3, slash, 5
- a simplified improper fraction, like 7 / 4 7/4 7 / 4 7, slash, 4
- a mixed number, like 1 3 / 4 1\ 3/4 1 3 / 4 1, space, 3, slash, 4
- an exact decimal, like 0.75 0.75 0 . 7 5 0, point, 75
- a multiple of pi, like 12 pi 12\ \text{pi} 1 2 pi 12, space, start text, p, i, end text or 2 / 3 pi 2/3\ \text{pi} 2 / 3 pi 2, slash, 3, space, start text, p, i, end text

## Vertical Angles

Vertical Angles are the angles opposite each other when two lines cross

## Example: a° and b° are vertical angles.

The interesting thing here is that vertical angles are equal :

(in fact they are congruent angles )

Have a play with them yourself. Notice how the 4 angles are actually two pairs of "vertical angles":

## Example: Find angles a°, b° and c° below:

Because b° is vertically opposite 40°, it must also be 40°

A full circle is 360°, so that leaves 360° − 2×40° = 280°

Angles a° and c° are also vertical angles, so must be equal, which means they are 140° each.

Answer: a = 140° , b = 40° and c = 140° .

## Vertical Angles

In these lessons, we will learn

- how to identify vertical angles,
- the vertical angle theorem,
- how to solve problems involving vertical angles,
- how to proof vertical angles are equal.

Related Pages Angles Pairs Of Angles Types Of Angles More Geometry Lessons

The Vertical Angle Theorem states that Vertical angles are equal.

Notice also that x and y are supplementary angles i.e. their sum is 180°.

The following diagram shows another example of vertical angles.

The following video explains more about vertical angles.

How to define and identify vertical angles?

A group of examples that identifies vertical angles.

## Solving Problems using Vertical Angles

Example: Given the diagram below, determine the values of the angles x , y and z .

Solution: Step 1: x is a supplement of 65°. Therefore, x + 65° = 180° ⇒ x = 180° 65° = 115°

Step 2: z and 115° are vertical angles. Therefore, z = 115°

Step 3: y and 65° are vertical angles. Therefore, y = 65°

Answer: x = 115°, y = 65° and z = 115°

Example: Both AEC and DEB are straight lines. Find q .

Solution: ∠AEB = ∠DEC ← vertical angles q + 45˚= 135˚ q = 135˚ – 45˚ = 90˚

The following video shows how to find a missing vertical angle in a triangle.

## Proof of the Vertical Angle Theorem

The following videos will prove that vertical angles are equal.

## IMAGES

## VIDEO

## COMMENTS

The intersecting lines on the dartboard form 10 pairs of vertical angles. The angles lie opposite of each other on the board and share the same measurement. The bull’s eye in the center of the board serves as the vertex.

Opposite angles, known as vertically opposite angles, are angles that are opposite to each other when two lines intersect. Vertically opposite angles are congruent, meaning they are equal in degrees of measurement.

A reference angle is an angle formed by the x-axis and the terminal side of a given angle, excluding quadrantal angles. It is a helpful tool when finding the values of trigonometric functions belonging to particular angles.

If the angles are vertical, then they are congruent, or the same measure. Therefore, if a vertical equals 3x and the other equals 80-x, you would simply set up

Equation practice with vertical angles. CCSS.Math: 8.EE.C.7, 8.EE.C.7b. Problem. Solve for x x xx: Created with Raphaël 7 x + 15 6 ∘ 7x + 156^\circ

Watch and learn how to find the measure of vertical angles by setting expressions equal to each other.

Vertical angles are congruent, so set the angles equal to each other and solve for x . Then go back to find the measure of each angle.

Step 1: Set the expressions labeling the angles equal to each other. Step 2: Isolate the variable on one side of

Solving Equations Involving Vertical Angles · 1. Find the value of x x by analyzing the relationship of vertical angles below. · 2. Which corresponds to the value

Angles a° and c° are also vertical angles, so must be equal, which means they are 140° each. Answer: a = 140°, b = 40° and c = 140°. Note: They are also called

In geometry, pairs of angles can relate to each other in several ways. When two lines intersect, the opposite angles form vertical angles or vertically opposite

b. a3 and a4 are neither vertical angles nor a linear pair. ... Practice and Applications.

and they form a straight line when they are next to one another. You can solve for missing supplementary angles to see why

Vertical angles practice problem. Find missing angles given one angle. First, identify the two sets of vertical angles. Angles