Lena's guest house is 15 m long and 12 m wide. how long is the diagonal of the house?

Imagine the diagonal of a rectangle being the split between two triangles. you are trying to find the longest side of the triangle, which is the "diagonal" of the rectangle.

to find the length of a side of a triangle, use the Pythagorean theorem. it is : a^2 + b^2 = c^2

so... plug in your data like this...

15^2 + 12^2= c^2.

225 + 144 = the square root of 369.

that is rounded to 19.2

this is just how I would solve this problem, if I helped you out please just let me know by voting me brainliest! :)