plzzz help find the probability that a randomly selected point within the circle falls in the red shaded area

Agroup of students want to create a garden. they do not know the exact measurements but they propose using a variable to represent the length and width of the garden. the length of the garden is 10 feet longer than double the width. use a single variable to write algebraic expressions for both the length and width of the garden. write an algebraic expression for the area of the garden. use mathematical terms to describe this expression.

What is the value of the discrimination for the quadratic equation 0=×2+2+×2

Will mark brainliest! ( explain the answer too, it can be one sentence)