Can someone plz help me

Match the term on the left with its image or description on the right. match term definition diameter a) circle a and a line segment connecting points b and c which are on the circle. circumference b) circle a and a line segment connecting points b and c which are on the circle. radius c) a piece of the circumference of a circle secant d) two circles that share the same center. concentric circles e) the distance around a circle arc f) a segment between two points on a circle that passes through its center

Which expression gives the area of the triangle shown below

Look at this pattern ; 1,4,9, number 10000 belongs in this pattern . what’s the place of this number?