If the side length of a regular Pentagon is a, the area of the regular Pentagon is 5√2a/2, so the area of the ark is 5√2a/4, and the area of the ark is equal to the area of a right triangle+the area of an obtuse triangle, that is, (AB*a/2)a2+AC*a/2. So (AB*a/2)/2+AC*a/2=5√2a/4. Say no to a Get AC+ 1/2AB=5√2/2.

√ is the root sign/can be regarded as the division sign * is the multiplication sign.

I spent an hour on this topic ~ At the same time, for the sake of a junior high school graduate ~ Give me some ~ If you don't know anything, you can call me ~ This is my email address with QQ number chenze84 1355632@qq.com.