How to measure sumthing when its curved

So for like 100 points of my grade in my science call my teacher wants to know how can you measure a shape with a curved side a straight side he said there isnt a wrong or right aswer its just the best answer does anybody know ?
Thanks

use string hold it 1 end then place it along the curves and straights of whatever your measuring then cut it at the other end then put it on the floor straight and measure the string

I've seen it done with maps to get a distance by placing the string along the road then measuring it and working out the distance with the scale at the bottom lol

Well it all depends on it. A shape with a curved side and a straight side could be a perfect semi-circle. If it was, then you could just pretend it's a whole circle, determine the diameter or length or what have you, and then divide that by half. It all depends on what the specific shape IS.

you could find the measure of the arc for the curved side and then calculate the percentage of a circle with said arc. Then you add the length of the straight side and you have the circumference. I wouldn't know how to do the area, though.

its a square but 1 side is curved