Question 19
In the diagram, $ABCD$ is a rectangle with $AD=30$ cm. Triangle $ECF$ is right-angled at $C$, $CF=48$ cm, and $A,E,F$ are collinear. The area of triangle $AEC$ is 240 square centimetres. Find the area of triangle $ABE$, in square centimetres.
Answer format: enter one whole number without units. The printed paper uses four answer-sheet digits with leading zeros when needed; ordinary numeric entry is used here.
Answer format: enter one whole number without units. The printed paper uses four answer-sheet digits with leading zeros when needed; ordinary numeric entry is used here.