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Course: 6th grade (Eureka Math/EngageNY) > Unit 5
Lesson 1: Topic A: Area of triangles, quadrilaterals, and polygons- Area of a parallelogram
- Area of parallelograms
- Area of parallelograms
- Finding height of a parallelogram
- Find missing length when given area of a parallelogram
- Area of a triangle
- Find base and height on a triangle
- Area of triangles
- Finding area of triangles
- Area of right triangles
- Area of triangles
- Triangle missing side example
- Find missing length when given area of a triangle
- Area of a triangle on a grid
- Area of a quadrilateral on a grid
- Area of quadrilateral with 2 parallel sides
- Area of trapezoids
- Area of trapezoids
- Area of kites
- Finding area by rearranging parts
- Area of composite shapes
- Decompose area with triangles
- Area of composite shapes
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Finding area of triangles
The area of a triangle is found by multiplying one half of the base by the height. In our example, the base is 18 and the height is 6. So, half of 18 is 9, and 9 times 6 equals 54 square units.
Video transcript
- [Instructor] What is
the area of the triangle? And they're talking
about this triangle here. And like always, pause this video and see if you can figure
it out on your own. All right, now let's
work through it together. So we know that the area of a triangle is going to be equal to 1/2 times our base times our height. Let me do the height in a different color. Times, times our height. So, what is the length of
our base in this scenario? Well, the base is this 18 right over here. Let me highlight it. This length right over here is our base. So the base is 18. And what is the height? Well, the height, we see, is six. They give it to us. They don't always give it to you, but in this example they do. So the height is, the height... The height is, I'm having
trouble with my pen, is six. So now we just have to compute what 1/2 times 18 times six is. Well, let's think about this a little bit. Well, 1/2 times 18 is nine. Nine times six is equal to what? Nine times six is equal to 54. And we are done. This is 54 square units.