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Two Sides from Hypotenuse and Angle

The side opposite the angle is the hypotenuse times the sine; the adjacent side is the hypotenuse times the cosine. Half their product is the area.

Your numbers

Side a

50cm

Side b

86.6cm

Area

2,165.06cm²

Formula

Side a = Hypotenuse × sin(Angle (°)), Side b = Hypotenuse × cos(Angle (°))

At 45 degrees the two legs are equal and the area is at its largest. Push the angle to 0 or 90 and the triangle flattens away.

What to enter

InputDefaultAccepted range
Hypotenuse (cm)The longest side of a right triangle, facing the right angle.1000 and up
Angle (°) (°)An angle in degrees; a full turn is 360°.300 ~ 90

Step by step

FormulaSide a = Hypotenuse × sin(Angle (°)), Side b = Hypotenuse × cos(Angle (°))
With the default numbersSide a = 100 × sin(30), Side b = 100 × cos(30)
AnswerSide a = 50 cm

Quick reference table

Results when only Hypotenuse (cm) changes and everything else stays put.

Hypotenuse (cm)Side a (cm)Side b (cm)Area (cm²)
502543.3541.27
7537.564.951,217.85
1005086.62,165.06
15075129.94,871.39
200100173.218,660.25

What each result means

ResultAt default values
Side a (cm)The length of the first side.50
Side b (cm)The length of the second side.86.6
Area (cm²)The space a shape covers — length squared.2,165.06

Common mistakes

At 45 degrees the two legs are equal and the area is at its largest. Push the angle to 0 or 90 and the triangle flattens away.

Glossary

Hypotenuse
The longest side of a right triangle, facing the right angle.
Angle (°)
An angle in degrees; a full turn is 360°.
Side a
The length of the first side.
Side b
The length of the second side.
Area
The space a shape covers — length squared.

Frequently asked questions

Q. How is Two Sides from Hypotenuse and Angle calculated?

Side a = Hypotenuse × sin(Angle (°)), Side b = Hypotenuse × cos(Angle (°)) — The side opposite the angle is the hypotenuse times the sine; the adjacent side is the hypotenuse times the cosine. Half their product is the area.

Q. Can you walk through an example?

With Hypotenuse 100cm, Angle (°) 30°, the answer is Side a 50cm.

Q. What do I need to enter?

Enter Hypotenuse, Angle (°). The result recalculates as you type, and an empty box counts as zero.

Q. How much does the answer move if I change a number?

Changing only Hypotenuse (cm) moves the answer to Hypotenuse (cm) 50 → Side a (cm) 25 and Hypotenuse (cm) 200 → Side a (cm) 100. The table below lays out five steps.

Q. How are the numbers rounded?

Money is shown to the nearest whole unit, percentages to one decimal place and everything else to two. What you see is rounded; the calculation itself carries the unrounded value forward.

Q. Anything to watch out for?

At 45 degrees the two legs are equal and the area is at its largest. Push the angle to 0 or 90 and the triangle flattens away.

Related calculators

Keep your length units consistent across inputs — mixing centimetres and metres throws results far off.