On the Subject of Flyswatting

Damn. I thought humanity was getting better but now they decided to put the most annoying activity that has ever existed on this Earth on a &&$&*ing bomb...

This module consists of 5 flies with a letter on them and 3 numbers in the corners of the module. Use the diagram below to determine which flies can be swatted. If an incorrect fly is swatted, a strike will occur. To find the flies that need to be swatted, make three straight lines using the corners which have the numbers in the corners of the module to form a triangle. Any letters on the inside of the triangle represent flies which can be swatted, and letters outside of the triangle must be avoided.