Save guides, add subjects and pick up where you left off with your BBC account. The sides of right-angled triangles are labelled opposite, hypotenuse and adjacent. Trigonometry explores the ...

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The only way to work out an angle in a scalene triangle is if we know the other two angles. Right-angled triangle. A right-angled triangle is a triangle where one of the angles is 90 degrees.

The ancient Babylonians understood key concepts in geometry, including how to make precise right-angled triangles. They used this mathematical know-how to divide up farmland – more than 1000 ...

which states that "in a right-angled triangle the square of the hypotenuse is equal [to the sum of] the squares of the two other sides." Contrary to what generations of pupils have learned in high ...