The Sum of 8 and 7 doubled

Well, seven plus eight is fifteen. And fifteen plus fifteen in thirty, so 30 is your answer. ( :

What is your question?

“exterior angles of triangles. an exterior (or external) angle is the angle between one side of a triangle and the extension of an adjacent side. try this drag the orange dots on any vertex to reshape the triangle.” look to get to the answer i explained what it means and other things i hope it you .