Grade 8 Geometry Worksheets

How to solve Grade 8 geometry problems

Real problems from these worksheets, solved one step at a time — the same explanations your child sees when practicing online.

1. Example 1

   Point P(−3, −1) is reflected across the y-axis to P′. What is the x-coordinate of P′?

   1. Reflecting across the y-axis keeps y the same and changes the sign of x: (x, y) → (−x, y).
   2. P′ = (3, −1), so the x-coordinate is 3.

   Answer: 3

2. Example 2

   Triangle ABC is congruent to triangle DEF. Angle A measures 79° and angle B measures 25°. What is the measure of angle E, in degrees?

   1. Congruent figures have equal corresponding angles. Match the letters in order: A↔D, B↔E, C↔F.
   2. Angle E corresponds to angle B, so it measures 25°.

   Answer: 25

3. Example 3

   Two parallel lines are cut by a transversal. Two corresponding angles measure (3x + 8)° and 92°. What is the value of x?

   1. Corresponding angles are equal, so set the measures equal.
   2. 3x + 8 = 92
   3. 3x = 84
   4. x = 84 ÷ 3 = 28

   Answer: 28