Look at the triangle in the diagram. Calculate the length of side AC.
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Look at the triangle in the diagram. Calculate the length of side AC.
To solve the exercise, we have to use the Pythagorean theorem:
A²+B²=C²
We replace the data we have:
3²+4²=C²
9+16=C²
25=C²
5=C
5 cm
Consider a right-angled triangle, AB = 8 cm and AC = 6 cm.
Calculate the length of side BC.
The hypotenuse is always the longest side and sits opposite the right angle (the 90° corner). In this triangle, AC is opposite the right angle at B, making it the hypotenuse.
The Pythagorean theorem requires squaring each leg, not just adding them. Think of it as finding the area of squares built on each side: 3² = 9 square units, 4² = 16 square units.
Many triangles give irrational numbers like . The 3-4-5 triangle is special because it gives a whole number answer - that's why it's called a Pythagorean triple!
No! The Pythagorean theorem only works for right triangles. You must have a 90° angle. For other triangles, you need different formulas like the Law of Cosines.
The 3-4-5 triangle is the most common Pythagorean triple. Remember it as a scaling pattern: 6-8-10, 9-12-15, etc. All follow the same ratio!
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