Work out the area of triangle ABC?
1 Answer
Apr 17, 2018
Explanation:
#"area of "triangleABC=1/2xx"base"xx"height"#
#color(white)(xxxxxxxxxxxx)=1/2xxACxxBD#
#triangleABD" is a right triangle"#
#"using "color(blue)"Pythagoras' theorem"#
#AB^2=AD^2+BD^2#
#rArrBD=sqrt(AB^2-AD^2)#
#color(white)(rArrBD)=sqrt((2sqrt5)^2-(3sqrt2)^2)#
#color(white)(rArrBD)=sqrt(20-18)=sqrt2#
#rArr"area of "triangleABC=1/2xx4sqrt2xxsqrt2#
#color(white)(xxxxxxxxxxxxxx)=2xx2=4" units"^2#