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Area and perimeter of a right-angled triangle

right-angled triangle

right-angled triangle A B C a b c hc cb ca α β
a, blegs
chypotenuse
hcheight to edge c
α, βangle

Calculator

Select the units of measurement

Enter 2 values

leg

a =

leg

b =

hypotenuse

c =

angle

α =

angle

β =

height to edge c

hc =

area

A =

perimeter

P =

Error

Round to decimal place

Calculation procedure

Formulas

right-angled triangle

area
$$ A = \frac{a b}{2} = \frac{c h_c}{2} $$
perimeter
$$ P = a + b + c $$
Pythagorean theorem
$$ c^2 = a^2 + b^2 $$
height to edge c
$$ h_c = a \cdot\sin\beta = b \cdot\sin\alpha $$
angle
$$ \alpha + \beta = 90^\circ $$
trigonometric functions
$$ \begin{aligned} \sin\alpha &= \frac{a}{c} \\ \\ \cos\alpha &= \frac{b}{c} \\ \\ \tan\alpha &= \frac{a}{b} \\ \\ \cot\alpha &= \frac{b}{a} \end{aligned} $$
$$ \begin{aligned} a^2 &= c \cdot c_a \\ \\ b^2 &= c \cdot c_b \\ \\ h_c^2 &= c_a \cdot c_b \end{aligned} $$

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