Someone wanna help me out with Tetris Transformation desmos ?? Anything would help!

Can someone me my sister? she is in third grade. 50 points and brainlist! ones that are not answered. plz and thx!

Atriangle has a side lengths of 18cm, 80 cm and 81cm. classify it as acute obtuse or right?

Find the volume of the solid whose base is the region bounded by f(x), g(x) and the x-axis on the interval [0, 1], and whose cross-sections perpendicular to the y-axis are squares. your work must show the integral, but you may use your calculator to evaluate it. give 3 decimal places for your answe