USA quiz · Grade 8

Grade 8 Pre-Algebra quiz

16 practice questions. Tap an answer, then use the list below to study with a parent or teacher.

Question and answer list

Open a card to see the answer. These are original practice items for US elementary students — not a state test copy.

1. In y = mx + b, m is the

Answer: slope

Rise over run.

2. In y = mx + b, b is the

Answer: y-intercept

The line crosses the y-axis at (0, b).

3. Slope is calculated as

Answer: (y₂ − y₁) / (x₂ − x₁)

Vertical change over horizontal change.

4. A line with slope 0 is

Answer: horizontal

y does not change.

5. A vertical line has

Answer: undefined slope

You would divide by zero.

6. The slope of the line through (1, 2) and (3, 6) is

Answer: 2

(6 − 2) / (3 − 1) = 4/2 = 2.

7. y = −3x + 5 has a slope that is

Answer: negative, so the line falls left to right

Negative m means the line decreases.

8. Parallel lines have

Answer: the same slope

Perpendicular slopes are opposite reciprocals.

9. The Pythagorean theorem is

Answer: a² + b² = c²

Only for right triangles; c is the hypotenuse.

10. The hypotenuse is

Answer: the side opposite the right angle

It is the longest side.

11. If a = 3 and b = 4, c =

Answer: 5

9 + 16 = 25, √25 = 5.

12. If a = 5, b = 12, c =

Answer: 13

25 + 144 = 169, √169 = 13.

13. A 6-8-10 triangle is a

Answer: scaled 3-4-5 right triangle

Multiply 3-4-5 by 2.

14. If c = 10 and a = 6, b =

Answer: 8

36 + b² = 100 → b² = 64.

15. You can use the theorem to find

Answer: the distance between two points on a grid

Think of the legs as Δx and Δy.

16. The theorem does not apply to

Answer: a triangle with no right angle

All angles must include 90°.

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