Question

In the figure below, the lengths of DE , EF , and FG are given, in units. What is the area, in square units, of ∆DEG ?

Answer 1

I found `60u^2`

Explanation:

We can try evaluating the BIG area (the one of `DeltaDFG`) first and then subtract the SMALL area (the one of of `DeltaEFG`):
`Area_(DeltaDFG)=((12+7)*10)/2=95u^2`
`Area_(DeltaEFG)=(7*10)/2=35u^2`
and so:
`Area_(DeltaDEG)=95-35=60u^2`