#### Vertical angles are congruent (equal to each other), then:For example: angle FOE is vertical to BOC3X+10=70X=20Moreover, to solve Y,FOA is alsoVertical to COD then: 2Y=3Y-30Y=30°Substituting COD=2(30)=60°, AOF=3(30)-30=60°

Finally, to find Z, we know EOB is straight angle,
Z+60+70=180
Z=50°

When two parallel lines are crossed by another line
(called the transversal).
You need to remember which angles are equal to each other.

#### Triangles

A triangle is a closed figure with 3 sides.
The sum of the interior angles of any triangle is 180 degrees.

There are three different types of triangles depending on the sides and angles.
Let's see the different types of triangles and their properties:

#### Right Triangles

Any triangle with a 90°-degree angle is a right triangle.
The measurement of the sides of a right triangle can be calculated with the following formula:

where C is the hypotenuse, A and B are the legs of the triangle

Let's see the different types of triangles and their properties:

#### 45:45:90

The right triangle 45-45-90 follows the ratio

X:X:X√2
Let's do an example:

#### 30:60:90 Triangle

The right triangle 30:60:90 follows the ratio

X:X√3:2X
Let's do an example: