## How do you solve a triangle with parallel lines?

If a line parallel to one side of a triangle intersects the other two sides of the triangle, then the line divides these two sides proportionally. If ¯DE∥¯BC , then ADDB=AEEC .

**What is the formula for a 45 45 90 triangle?**

Using the pythagorean theorem – As a right angle triangle, the length of the sides of a 45 45 90 triangle can easily be solved using the pythagorean theorem. Recall the pythagorean theorem formula: a 2 + b 2 = c 2 a^2+b^2=c^2 a2+b2=c2.

**What are the formulas for a 30 60 90 triangle?**

In a 30-60-90 triangle, the ratio of the sides is always in the ratio of 1:√3: 2. This is also known as the 30-60-90 triangle formula for sides. y:y√3:2y.

### What are the relationship of the sides of a 30 60 90 triangle?

Remembering the 30-60-90 triangle rules is a matter of remembering the ratio of 1: √3 : 2, and knowing that the shortest side length is always opposite the shortest angle (30°) and the longest side length is always opposite the largest angle (90°).

**How do you find a right angled triangle?**

Key Takeaways

- The Pythagorean Theorem, a2+b2=c2, a 2 + b 2 = c 2 , is used to find the length of any side of a right triangle.
- In a right triangle, one of the angles has a value of 90 degrees.
- The longest side of a right triangle is called the hypotenuse, and it is the side that is opposite the 90 degree angle.

**How do you prove a line is parallel to a triangle?**

If a line lying outside a triangle is parallel to one side of the triangle and intersects the extensions of the other two sides of the triangle, then the line divides the extensions of those sides proportionally. If a line splits two sides of a triangle proportionally, then that line is parallel to the remaining side.

## What is the definition of the parallel line theorem?

This leads us to the definition of a theorem that links the line segments created when a parallel side is added to a triangle. If a line parallel to one side of a triangle intersects the other two sides of the triangle, then the line divides those sides proportionally.

**How do you find the proportional parts of similar triangles?**

Proportional Parts of Similar Triangles. Theorem 59: If two triangles are similar, then the ratio of any two corresponding segments (such as altitudes, medians, or angle bisectors) equals the ratio of any two corresponding sides. In Figure 1, suppose Δ QRS∼ Δ TUV. Figure 1 Corresponding segments of similar triangles.

**What are the axioms of parallel lines?**

Corresponding angles are equal. Vertical angles/ Vertically opposite angles are equal. Alternate interior angles are equal. Alternate exterior angles are equal. Pair of interior angles on the same side of the transversal are supplementary. Go through the following axioms and theorems for the parallel lines.

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