Which is true regarding chords and diameters of circles?
both chords and diameters have two endpoints on a circle. diameters must intersect the center of a circle.
both chords and diameters have two endpoints on a circle. chords must intersect the center of a circle.
chords have two endpoints on a circle. diameters have one endpoint on a circle and one at the center.
chords have one endpoint on a circle and one at the center. diameters have two endpoints on a circle.

the correct answers are the following:

1. both chords and diameters have two endpoints on a circle.

this is true. chords are straight lines whose endpoints lie on a circle. this is indicated as the red line in figure 1. notice that the endpoints lie on the circle. on the other hand, diameters also have two endpoints on a circle as indicates the blue line in figure 2.

2. diameters must intersect the center of a circle.

this is true. one important feature of diameters is that they must intersect the center of the circle. this is shown in figure 2. so, diameters are:

circle area = pi * radius^2

if diameter = 10 then radius = 5

circle area = pi * 5^2

circle area = pi * 25

circle area = 78.5398163397 square units

step-by-step explanation: