The answer to each word problem is scalene because each triangle created has different side lengths.

Two children are skiing behind a boat. Child A has 45 foot long rope, and child B has a 50 foot rope. If they remain 10 feet apart,which of the following triangles is created? Isosceles,Scalene,Equilateral

Carpenters are laying a foundation to a house, and use an old trick. They create a triangle using a 3,4, and 5 foot long piece of lumber. This combination creates a 90 degree angle for the foundation. Which of the following triangles was created? Isosceles,Equilateral,Scalene

* A scalene triangle has three sides of different lengths, which results in three angles of different angle measures.

*Like all triangles, the angles of a scalene add up to 180 degrees.

*A right triangle can be a scalene triangle, but an isosceles triangle cannot because it has two equal sides.

*The vertex of a scalene triangle is the point where two lines meet and form a corner. Like every triangle a scalene has three vertices.

*Any side of a scalene triangle can be the base.

*A **30-60-90 **right triangle is a scalene triangle; however a **45-45-90** is not.

*A scalene does not have a **line of symmetry**. If you can fold an image or object ,and both sides exactly match, then you can draw a “line of symmetry.”

*The **altitude** is measured by drawing a perpendicular line from the base to the opposite vertex.

*There can be three different altitudes depending on the base used.

*The three altitudes of a scalene triangle intersect at a point called the orthocenter.

Transcript

Welcome to MooMooMath. Today we are talking about Scalene Triangles. A scalene triangle is one in which all three angles are different. So let’s look at two examples. I’m going to mark these triangles 3 inches, 4 inches, and 5 inches. All three sides are different lengths. This triangle over here is marked such that all three sides are the same. The mark on the side represents equal lengths. This is actually an equilateral triangle. Now let’s look at a scalene triangle based on angles. You have a forty five degree angle, a forty five degree angle, and a ninety degree angle, and over here you have a 60 degree angle, a 30 degree angle, and a ninety degree angle. So based on angles which of these is a scalene angle? This one here (circles the triangle with 60, 30, 90 degree angles) because all three angles are different or all three sides are different. The other triangle these two angles are the same meaning these two legs are the same so this one is actually what they call an isosceles triangle. So let’s look at the rules. The definition is all sides are different lengths and all angles are different measures. So our 3, 4, 5, is our example. Hope this video was helpful.

This *scalene triangle* has three sides with different lengths

A right triangle can be a *scalene triangle*

This scalene triangle has three angles with different measures,which creates three different side lengths.

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Find the area of a *scalene triangle* using **1/2 base x height**

Height

Base

Any **side **can be used as the **base**. However if the height is given, the base will be perpendicular to the height

Height not known

Base

a

If the **height** is unknown you can use *Heron's Formula*

b

c

Height not known

Base

a

b

c

Find the perimeter of a **scalene triangle **using a +b+c

(In other words just add the length of all three sides.)

Roof Truss

Let's look at some examples of *Scalene Triangles*

Two sides of every 45 45 90 are equal.