question_answer 14)

ABC is a triangle right-angled at C. If \[\text{AB}=\text{25 cm}\] and \[\text{AC}=\text{7 cm},\] find BC

Answer:

\[A{{C}^{2}}+B{{C}^{2}}=A{{B}^{2}}\] \[\left| ~\text{By Pythagoras Property} \right.\]     \[\Rightarrow \]               \[{{7}^{2}}+B{{C}^{2}}={{25}^{2}}\] \[\Rightarrow \]               \[49+B{{C}^{2}}=625\] \[\Rightarrow \]               \[B{{C}^{2}}=625-49\] \[\Rightarrow \]               \[B{{C}^{2}}=576\] \[\Rightarrow \]               \[BC=\text{24 cm}\].