Angles T and V are complementary. Angle T has a measure of (2x + 10)°. Angle V has a measure of 48°. What is the value of x?

You are standing next to a really big circular lake. you want to measure the diameter of the lake, but you don't want to have to swim across with a measuring tape! you decide to walk around the perimeter of the lake and measure its circumference, and find that it's 400\pi\text{ m}400? m. what is the diameter dd of the lake?