I know and this is what confuses me. You can express the area in terms of ##\phi## yes, but this won't get me anywhere. I have written the question essentially the same, so maybe there is an error with the question.
Homework Statement
Here is the question given:
A blade for a lawnmower consists of two parts made of the same material and joined together as shown:
The length OP is one unit in length and MPQN is square in shape.
Develop an equation for the cross-sectional area of the blade and...