Thank you for the expert s answer. Trouble answer, thank you.

With auxiliary lines, the triangle ABC is similar to the triangle ace, so the triangle ABC is also an isosceles triangle, so ab=cb

In this way, the area of the sector AOB is the same as that of the sector COB;

So you only need to calculate the area of the two triangles;

Study well.

It's better than finding someone to help you with your homework.

At 4:45 a.m., when I was listening to this song under the covers, I couldn't help but tears fell, snot bubbles burst one after another, and my throat kept sobbing and whin......ingThese spicy strips are so delicious