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EasyTrianglesGeometry0:42

The Pythagorean Theorem

Use a² + b² = c² to find the hypotenuse of a right triangle with legs 6 and 8, then check the answer with the converse.

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Narrated by a synthetic voice (Piper TTS, en_US-ljspeech-high voice (LJ Speech dataset, public domain)). Download MP4 (0.4 MB) · Captions (WebVTT)

On-screen maths

Every board from the lesson, so you can read it at your own pace or copy it into your notes.

1. The theorem0:00
$a^2 + b^2 = c^2$
2. Legs 6 and 80:12
3. Solve0:17
1. $6^2 + 8^2 = c^2$
2. $36 + 64 = 100 = c^2$
3. $c = \sqrt{100} = 10$
4. Recap0:31
- Only for right triangles.
- $c$ is always the longest side.
- Take the positive square root for a length.

About triangles

Angle sum, congruence, similarity and the Pythagorean theorem.

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