Why is the opposite of a number also called the additive inverse

Television sizes are based on the length of the diagonal of the television's rectangular screen. so, for example, a 70-inch television is a television having a diagonal screen length of 70 inches. if a 70 inch television's diagonal forms a 29°angle with the base of the screen, what is the vertical height (1) of the screen to the nearest inch? 70 inhin

Meg constructed triangle poq and then used a compass and straightedge to accurately construct line segment os, as shown in the figure below, which could be the measures of angles pos and angle poq?

Emily convinced her mom to buy a giant box of her favorite cereal. her mom doesn't think the box will fit on their shelf. the volume of the box is 1000 cm^3 . the base of the box is 25 cm by 10 cm