Right Isosceles Triangle
 Right isosceles triangle (a twodimensional figure) has one side a right 90° interior angle and the other two angles are 45°.
 Angle bisector of a right isosceles triangle is a line that splits an angle into two equal angles.
 Circumcircle is a circle that passes through all the vertices of a twodimensional figure.
 Hypotenuse of a right isosceles triangle is the longest side or the side opposite the right angle.
 Inscribed circle is the Iargest circle possible that can fit on the inside of a twodimensional figure.
 Median of a right isosceles triangle is a line segment from a vertex (coiner point) to the midpoint of the opposite side.
 Semiperimeter is one half of the perimeter.
 Side of a right triangle is one half of the perimeter.
 Two sides are congruent.
 3 edges
 3 vertexs
 a = opposite leg
 b = adjacent leg
 c = hypotenuse
 Angles: ∠A, ∠B, ∠C
 Height: \(h_a\), \(h_b\), \(h_c\)
 Median: \(m_a\), \(m_b\), \(m_c\) – A line segment from a vertex (corner point) to the midpoint of the opposite side
 Angle bisectors: \(t_a\), \(t_b\), \(t_c\) – A line that splits an angle into two equal angles


\(\large{ t_a = 2\;b\;c \;\; cos \; \frac { \frac {A}{2} }{ b \;+\; c } }\) \(\large{ t_a = \sqrt { bc \; \frac { 1 \;\; a^2 } { \left( b \;+\; c \right)^2 } } }\) \(\large{ t_b = 2\;a\;c \;\; cos \; \frac { \frac {B}{2} }{ a \;+\; c } }\) \(\large{ t_b = \sqrt { a\;c \; \frac { 1 \;\; b^2 } { \left( a \;+\; c \right)^2 } } }\) \(\large{ t_c = a\;b \; \sqrt { \frac { 2 }{ a \;+\; b } } }\) 

Symbol  English  Metric 
\(\large{ t_a, t_b, t_c }\) = angle bisector  \(\large{ in }\)  \(\large{ mm }\) 
\(\large{ A, B, C }\) = angle  \(\large{ deg }\)  \(\large{ rad }\) 
\(\large{ a, b, c }\) = edge  \(\large{ in }\)  \(\large{ mm }\) 


\(\large{ A_{area} = \frac {h\;b} {2} }\) \(\large{ A_{area} = \frac {1} {2}\; b\;h }\) \(\large{ A_{area} = a\;b\; \frac {\sin \;y} {2} }\) 

Symbol  English  Metric 
\(\large{ A_{area} }\) = area  \(\large{ in^2 }\)  \(\large{ mm^2 }\) 
\(\large{ a, b, c }\) = edge  \(\large{ in }\)  \(\large{ mm }\) 
\(\large{ h }\) = height  \(\large{ in }\)  \(\large{ mm }\) 


\(\large{ R = \frac { 1 } { 2 } \; \sqrt { a^2 + b^2 } }\) \(\large{ R = \frac { H } { 2 } }\) 

Symbol  English  Metric 
\(\large{ R }\) = outcircle  \(\large{ in }\)  \(\large{ mm }\) 
\(\large{ a, b, c }\) = edge  \(\large{ in }\)  \(\large{ mm }\) 
\(\large{ H }\) = hypotenuse  \(\large{ in }\)  \(\large{ mm }\) 


\(\large{ h_c = 2\; \frac {A_{area}}{b} }\)  
Symbol  English  Metric 
\(\large{ h^c }\) = height  \(\large{ in }\)  \(\large{ mm }\) 
\(\large{ A_{area} }\) = area  \(\large{ in^2 }\)  \(\large{ mm^2 }\) 
\(\large{ a, b, c }\) = edge  \(\large{ in }\)  \(\large{ mm }\) 


\(\large{ r = \frac { a \;+\; b \;\; c } { 2 } }\)  
Symbol  English  Metric 
\(\large{ r }\) = incircle  \(\large{ in }\)  \(\large{ mm }\) 
\(\large{ a, b, c }\) = edge  \(\large{ in }\)  \(\large{ mm }\) 


\(\large{ m_a = \sqrt { \frac { 4\;b^2 \;+\; a^2 }{ 2 } } }\) \(\large{ m_b = \sqrt { \frac { 4\;a^2 \;+\; b^2 }{ 2 } } }\) \(\large{ m_c = \frac {c} {2} }\) 

Symbol  English  Metric 
\(\large{ m_a, m_b, m_c }\) = median  \(\large{ in }\)  \(\large{ mm }\) 
\(\large{ a, b, c }\) = edge  \(\large{ in }\)  \(\large{ mm }\) 


\(\large{ P = a + b + c }\)  
Symbol  English  Metric 
\(\large{ P }\) = perimeter  \(\large{ in }\)  \(\large{ mm }\) 
\(\large{ a, b, c }\) = edge  \(\large{ in }\)  \(\large{ mm }\) 


\(\large{ a = P – b – c }\) \(\large{ a = 2\; \frac {A_{area}} {b\;\sin y} }\) \(\large{ b = P – a – c }\) \(\large{ b = 2\; \frac {A_{area}}{h} }\) \(\large{ c = P – a – b }\) 

Symbol  English  Metric 
\(\large{ a, b, c }\) = edge  \(\large{ in }\)  \(\large{ mm }\) 
\(\large{ A_{area} }\) = area  \(\large{ in^2 }\)  \(\large{ mm^2 }\) 
\(\large{ P }\) = perimeter  \(\large{ in }\)  \(\large{ mm }\) 

Find A 
Find B 
Find a 
Find b 
Find c 
Find Area 