Work out the area of triangle ABC?
1 Answer
May 20, 2018
Explanation:
#"the area (A) of "triangleABC" is calculated using"#
#•color(white)(x)A=1/2bh#
#"where b is the base and h the perpendicular height"#
#"here "b=AC" and "h=BD#
#AC=3sqrt5+sqrt5=4sqrt5#
#"calculate BD using "color(blue)"Pythagoras' theorem "#
#triangleABD#
#AB^2=AD^2+BD^2#
#rArrBD=sqrt(AB^2-AD^2)#
#color(white)(rArrBD)=sqrt((5sqrt2)^2-(3sqrt5)^2)#
#color(white)(rArrBD)=sqrt(50-45)=sqrt5#
#rArrA=1/2xx4sqrt5xxsqrt5=10" cm"^2#