Anyone have an idea?

What are the measures of ∠a, ∠b, ∠c and ∠d? explain how to find each of the angles. measure need asap

An equation where variables are used to represent known values—function notation true or false

To solve the system of equations below, pedro isolated the variable y in the first equation and then substituted it into the second equation. what was the resulting equation? { 5y=10x {x^2+y^2=36