Someone help me I will make you

What aspects of lines have to be diffrent

Astuntman jumping off a 20-m-high building is modeled by the equation h=20-5t^2, where t is the same in seconds. a high-speed camera is ready to film him between 15m and 10m above the ground. for which interval of time should the camera film him?

Iwill give ! if m∠a=59 and m∠3=81°, what is m∠b? m∠b= _[blank]_°