The distance formula

Grade 10 Math Worksheet - Building Confidence

Circle the best answer.

1. 1.

   Ari's map has the library at A(-2, 3) and the park at B(4, -5). Which expression gives the straight-line distance AB?

   • √((4 − (-2))² + (-5 − 3)²)
   • √((4 − (-2)) + (-5 − 3))
   • (4 − (-2)) + (3 − (-5))
   • √((4 − 2)² + (-5 − 3)²)
2. 2.

   Bo's kite string runs from D(1, -2) to E(13, 3) on a grid in meters. How long is the string?

   • √145 m
   • 169 m
   • 13 m
   • 17 m
3. 3.

   Esme rides straight from the park at (2, 1) to the pool at (10, 7), with each unit 1 km. How far is that in a straight line?

   • 48 km
   • 100 km
   • 14 km
   • 10 km
4. 4.

   Jun's robot goes from (0, 0) to (5, 5). Which is its straight-line distance?

   • 10
   • √10
   • 5√2
   • 50
5. 5.

   Kira's tent flap is a triangle with corners P(0, 0), Q(9, 0) and R(9, 12). What is its perimeter?

   • 42 cm
   • 54 cm
   • 36 cm
   • 21 cm
6. 6.

   Luz's quilt triangle has corners A(0, 0), B(4, 3) and C(8, 0). Is it isosceles?

   • Yes: AB = √(16 + 9) = 5 and BC = 5, while AC = 8
   • Yes: AC = 8 is the longest side, so the other two must be equal
   • No: AB = 5, BC = 7 and AC = 8, so the three differ
   • No: the base AC = 8 is longer, so the sides cannot match
7. 7.

   A(1, 2) and B(x, 6) with AB = 5 and x > 0. Noah's point A is (1, 2) and B is (x, 6) with x positive. AB = 5. Which x works?

   • x = 4
   • x = 3
   • x = 10
   • x = 6
8. 8.

   A triangle with corners at known coordinates. Pia wants to show a triangle on the grid is isosceles. Which check works?

   • Find all three side lengths with the distance formula and see if two are equal
   • Find the three slopes and see if two are equal
   • Find the midpoint of each side and compare them
   • Check that two corners have the same y-coordinate
9. 9.

   Tala finds AB, then wonders whether swapping the points to find BA changes the answer. What is true?

   • AB = BA if both points have positive coordinates, but not otherwise
   • AB = BA, because (x₂ − x₁)² = (x₁ − x₂)²
   • AB = BA if the points lie on a horizontal line, but not otherwise
   • BA is the negative of AB, since the subtraction flips sign
10. 10.

    Zee's circle has center O(-2, 3) and passes through P(1, -1). What is its radius?

    • √17
    • 25
    • 7
    • 5