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Hypotenuse, opposite, and adjacent

In a right triangle, the hypotenuse is the longest side, an "opposite" side is the one across from a given angle, and an "adjacent" side is next to a given angle.
We use special words to describe the sides of right triangles.
The hypotenuse of a right triangle is always the side opposite the right angle. It is the longest side in a right triangle.
A right triange A B C where Angle C is ninety degrees. Inside the triangle, an arrow points from point C to the hypotenuse. The hypotenuse is labeled hypotenuse.
The other two sides are called the opposite and adjacent sides. These sides are labeled in relation to an angle.
The opposite side is across from a given angle.
A right triange A B C where Angle C is ninety degrees. Inside the triangle, an arrow points from point A to side B C. Side B C is labeled opposite.
The adjacent side is the non-hypotenuse side that is next to a given angle.
A right triange A B C where Angle C is ninety degrees. Inside the triangle, an arrow points from point A to side A C. Side A C is labeled adjacent.
Putting it all together from the perspective of angle, A:
A right triange A B C where Angle C is ninety degrees. Side A B is labeled hypotenuse. Side B C is labeled opposite. Side A C is labeled adjacent. The angle of reference is at angle A.
And from angle, B:
A right triange A B C where Angle C is ninety degrees. Side A B is labeled hypotenuse. Side A C is labeled opposite. Side B C is labeled adjacent. The angle of reference is at angle B.

Practice

Problem 1
Relative to angle G, which side is the adjacent side?
A right triange E G M. The short leg is E M. The long leg is M G. The longest side is G E. The angle of reference is at angle G.
Choose 1 answer:
Choose 1 answer:

Why are these words important?

We're about to learn the trigonometric functions—sine, cosine, and tangent—which are defined using the words hypotenuse, opposite, and adjacent.

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