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## Geometry (all content)

### Course: Geometry (all content)>Unit 7

Lesson 9: Advanced area with triangles

# Area of diagonal-generated triangles

Watch Sal prove that the areas of the pairs of triangles generated by the diagonals of a rectangle are equal. Created by Sal Khan.

## Want to join the conversation?

• Does this work for all triangles?
• if there are two congruent triangles paired with other triangles that make up a rectangle, yes, but otherwise, no.
• So technically all you do is multiply hxw ? Im still confused.
• What he was doing in this video was proving that all of the triangles in the rectangle have the same area.
To find the area of a triangle, you must multiply half of the base times the height.
He used the height and width of the rectangle to figure out the height and base of the triangles.
• Does this work on all rectangles or only the ones that are made up of 2 equal squares?
• Can we get a circle video?
• How do you do this problem?
• How do you find the area of a triangle that is obtuse
• Why do you need to create the rectangle into 4 triangles? Cant you just find the area of the rectangle?