What is the ratio in simplest form of 68:84

Given: circle o, cd is diameter, chord ab || cd. arc ab = 74°, find arc ca.

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?

If m_b=mzd= 43, find mzc so that quadrilateral abcd is a parallelogram o 86 137 o 129 43 description