The vertices of a parallelogram are a(x1, y1), b(x2, y2), c(x3, y3), and d(x4, y4). which of the following must be true if parallelogram abcd is proven to be a rectangle?

Ihave a 69 and an 82. the 69 is worth 40% of my grade and the 82 is worth 15%. can someone tell me my current average grade.

∆abc is reflected across the x-axis and translated 2 units up to give the image ∆a'b'c' with coordinates a'(1, 1), b'(2, -1), c'(2, 1). what are the coordinates of the preimage ∆abc? a. a(-1, 1), b(-2, 3), c(-2, 1) b. a(1, 1), b(2, 3), c(2, 1) c. a(1, -3), b(2, -1), c(2, -3) d. a(1, -3), b(2, -5), c(2, -3)

The function v(r)=4/3pir^3 can be used to find the volume of air inside a basketball given its radius. what does v(r) represent