Two perpendicular legs
Leg a + Leg b
c = √(a²+b²); A = ab/2
Open calculator ↗GEOMETRY, ONE FIGURE AT A TIMERight triangle.
Right triangle.
Understand every measure.
Let the right angle do the work. Four free tools, clear formulas and a little discovery along the way.
Find your calculator ↗FIGURE 032D / REFERENCE DRAWING
RIGHT TRIANGLENOT TO SCALE
THE CALCULATOR DESK
Start with what you know.
4 calculators available
Hypotenuse and one leg
Hypotenuse c + Leg a
b = √(c²−a²)
Open calculator ↗Adjacent leg and acute angle
Adjacent leg b + Acute angle θ
a = b tan θ
Open calculator ↗Hypotenuse and acute angle
Hypotenuse c + Acute angle θ
a = c sin θ; b = c cos θ
Open calculator ↗MEET THE FIGURE
A right triangle, explained.
A right triangle has one angle of exactly 90 degrees. The sides meeting at that angle are its legs. The side opposite the right angle is the hypotenuse and is always the longest side.
Understand the properties ↗LOOK A LITTLE CLOSER
More than a formula.
A triangle with side lengths 3, 4 and 5 is a right triangle.
The hypotenuse must exceed either leg. Acute-angle calculators require an angle strictly between 0 and 90 degrees.
Explore three geometry facts ↗These tools use ideal Euclidean geometry. Every input must use the same unit. Numerical results are rounded and do not replace measurement, specialist design or safety checks. See worked examples.