Revision Note - Math - Measures, Shape and Space - Triangles

Result: $a+b+c=180^\circ$

Reference: $\angle$ sum of $\D… Read

Result: $a=b$

Reference: base $\angle$s, isos. $\Delta$… Read

1. Centroid of triangle
   

   Property: The three medians intersec

Condition: $a=b$

Reference: sides opp. eq. $\angle$s… Read

Condition: $a^2+b^2=c^2$

Result: The triangle is a right-… Read

1. Three corresponding sides equal
    

   Condition: $AB=PQ$, $BC=

1. Three corresponding angles equal
   

   Condition: $\angle A=\a

Result: $a+b=c$

Reference: ext. $\angle$ of $\Delta$… Read

Condition: $AB=BC$ and $AD//BE//CF$

Result: $DE=EF$

Refe… Read

1. Angle sum of polygon

   Angle sum of $n$-gon $=(n-2)\times180

Condition: $AD=DB$ and $AE=EC$

Result: $DE//BC$ and $BC=2… Read

1. Corresponding sides

   Condition: $\Delta ABC \cong \Delta X

1. Corresponding sides

   Condition: $\Delta ABC\sim\Delta XY

Condition: Right-angled triangle

Result: $a^2+b^2=c^2$… Read

Result: $AB+BCAC$, $AB+ACBC$ and $BC+ACAB$

Reference: tr… Read