All SAT Math Resources
Example Questions
Example Question #11 : How To Find The Length Of A Line With Distance Formula
In terms of , give the length of a segment on the coordinate plane with endpoints and .
The length of a segment with endpoints and can be calculated using the distance formula:
Setting and , and substituting:
The binomials can be rewritten using the perfect square trinomial pattern:
Simplify and collect like terms:
Example Question #11 : How To Find The Length Of A Line With Distance Formula
Give the length, in terms of , of a line segment on the coordinate plane whose endpoints are and .
The length of a segment with endpoints can be calculated using the distance formula
Substituting , and simplifying"
Example Question #21 : Distance Formula
Find the length of a line segment whose endpoints are located at the coordinates and .
According to the distance formula, the linear distance between two points and is given by
,
which is a generalization of the Pythagorean Theorem for any two points on the coordinate plane.
The two points given in this problem are and . Although the question asks for the length of a line segment given its two endpoints, the distance formula is applicable here because the geometric meaning of "distance between two points" is the length of a line segment. Hence, we can use the distance formula to determine the distance between these two endpoints as shown:
Hence, the line segment bounded by the points and is units long.
Example Question #21 : How To Find The Length Of A Line With Distance Formula
One line has four collinear points in order from left to right A, B, C, D. If AB = 10’, CD was twice as long as AB, and AC = 25’, how long is AD?
50'
45'
35'
30'
40'
45'
AB = 10 ’
BC = AC – AB = 25’ – 10’ = 15’
CD = 2 * AB = 2 * 10’ = 20 ’
AD = AB + BC + CD = 10’ + 15’ + 20’ = 45’
Example Question #1 : Midpoint Formula
The midpoint of line segment AB is (2, -5). If the coordinates of point A are (4, 4), what are the coordinates of B?
(0, -13)
(6, 14)
(3, -0.5)
(6, 13)
(0, -14)
(0, -14)
The fastest way to find the missing endpoint is to determine the distance from the known endpoint to the midpoint and then performing the same transformation on the midpoint. In this case, the x-coordinate moves from 4 to 2, or down by 2, so the new x-coordinate must be 2-2 = 0. The y-coordinate moves from 4 to -5, or down by 9, so the new y-coordinate must be -5-9 = -14.
An alternate solution would be to substitute (4,4) for (x1,y1) and (2,-5) for (x,y) into the midpoint formula:
x=(x1+x2)/2
y=(y1+y2)/2
Solving each equation for (x2,y2) yields the solution (0,-14).
Example Question #2 : Midpoint Formula
Point A is (5, 7). Point B is (x, y). The midpoint of AB is (17, –4). What is the value of B?
(12, –11)
(8.5, –2)
None of the other answers
(22, –9)
(29, –15)
(29, –15)
Point A is (5, 7). Point B is (x, y). The midpoint of AB is (17, –4). What is the value of B?
We need to use our generalized midpoint formula:
MP = ( (5 + x)/2, (7 + y)/2 )
Solve each separately:
(5 + x)/2 = 17 → 5 + x = 34 → x = 29
(7 + y)/2 = –4 → 7 + y = –8 → y = –15
Therefore, B is (29, –15).
Example Question #1 : Midpoint Formula
Line segment AB has an endpoint, A, located at , and a midpoint at . What are the coordinates for point B of segment AB?
The second endpoint cannot exist
With an endpoint A located at (10,-1), and a midpoint at (10,0), we want to add the length from A to the midpoint onto the other side of the segment to find point B. The total length of the segment must be twice the distance from A to the midpoint.
A is located exactly one unit below the midpoint along the y-axis, for a total displacement of (0,1). To find point B, we add (10+0, 0+1), and get the coordinates for B: (10,1).
Example Question #3 : Midpoint Formula
Solve each problem and decide which is the best of the choices given.
What is the distance between the points and on a standard coordinate plane?
Make a triangle. The points are 8 units apart on the -axis, and units apart on the -axis. Then use the Pythagorean Theorem to find the distance of the hypotenuse, which ends up being .
Another way to solve this problem is to use the distance formula,
Plugging in the two points we get,
Example Question #1 : How To Find The Midpoint Of A Line Segment
A line segment has endpoints (0,4) and (5,6). What are the coordinates of the midpoint?
(0,6)
(0,4)
(2.5,5)
(2.5,-5)
(3,9)
(2.5,5)
A line segment has endpoints (0,4) and (5,6). To find the midpoint, use the midpoint formula:
X: (x1+x2)/2 = (0+5)/2 = 2.5
Y: (y1+y2)/2 = (4+6)/2 = 5
The coordinates of the midpoint are (2.5,5).
Example Question #1 : Midpoint Formula
Find the midpoint between (-3,7) and (5,-9)
(4,-1)
(1,-8)
(-1,-1)
(1,-1)
(4,-8)
(1,-1)
You can find the midpoint of each coordinate by averaging them. In other words, add the two x coordinates together and divide by 2 and add the two y coordinates together and divide by 2.
x-midpoint = (-3 + 5)/2 = 2/2 = 1
y-midpoint = (7 + -9)/2 = -2/2 = -1
(1,-1)