Find missing angles (straight line, corner, crossing lines)

Answer Key - Grade 7 Math Worksheet - Challenge Me

Circle the best answer, or write your answer on the line.

1. 1.

   Kira draws a line out from the square corner of an envelope for a secret-club stamp. It splits the corner into complementary angles, 28° and (4x + 10)°. What is x?

   13
2. 2.

   Luz tapes a streamer out from the square corner of the art table. It splits the corner into 19° and (3x + 17)°. What is x?

   18
3. 3.

   Pia's tent poles cross at the top. The (6x + 18)° angle is across from the 138° angle. What is x?

   20
4. 4.

   Three straight streets meet at one point on Tala's town map. Two angles are marked 48° and 73°, as the sketch shows. What is angle x, in degrees?

   59
5. 5.

   Bo's desk lamp arm leans on the flat desk. The angles on each side of the arm are (3x)° and (2x + 15)°. How big is the (2x + 15)° angle, in degrees?

   81
6. 6.

   Esme draws a line out from the square corner of a poster. It splits the corner into (2x)° and (3x + 5)°. How big is the (3x + 5)° angle, in degrees?

   56
7. 7.

   Jun tapes a paper snowflake chain out from the square corner of a window. It splits the corner into (4x)° and (2x + 6)°. How big is the (2x + 6)° angle, in degrees?

   34
8. 8.

   Ren folds a paper pinwheel with four blades from one center point (it spins wobbly). The angles are 60°, 80°, x° and (3x)°. What is x?

   55
9. 9.

   Four spokes on Tala's bike wheel are painted. The angles between them around the hub are 75°, 45°, x° and (2x)°. What is x?

   80
10. 10.

    Ari's toy sailboat has a triangle sail. The sail's angles are (2x)°, (2x + 6)° and 74°. What is x?

    25