Answer:
![9.91](https://img.qammunity.org/2023/formulas/mathematics/high-school/1pokil9ksu8g40e7gm17ntcinzlzkd1e91.png)
Explanation:
Since we know the shape is a square, all vertices should be the same length. Find the length of one vertex, by finding the distance between any two points. The following equation uses points
and
:
![d = √((x_2-x_1)^2 + (y_2-y_1)^2)\\d = √((1 - 1)^2 + (8-1)^2)\\d = √((0)^2 + (7)^2)\\d = √(49)\\d = 7](https://img.qammunity.org/2023/formulas/mathematics/high-school/9b3h08tbxpgadm40ktgsivykis6n2w0th9.png)
Since the distance is 7, for all sides use the Pythagorean theorem to find the diagonal:
![a^2 + b^2 = c^2\\7^2 + 7^2 = c^2\\49 + 49 = c^2\\98 = c^2\\√(98) = c\\c \approx 9.91](https://img.qammunity.org/2023/formulas/mathematics/high-school/xb5689yqzltqlmvc3hatkzf0oxm4pioifv.png)