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.

   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
2. 2.

   Milo's scissor blades cross like an X. The (4x + 12)° and 112° angles are vertical angles, across from each other. What is x?

   25
3. 3.

   Ren cuts a pizza with three straight cuts through the middle, making six slices. Two angles are marked 52° and 67°, as the sketch shows. What is angle x, in degrees?

   61
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.

   Zee draws a slightly lopsided snowflake from three straight lines crossing at the center. Two angles are marked 57° and 69°, as the sketch shows. What is angle x, in degrees?

   54
6. 6.

   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
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.

   Milo stitches two lines out from the square corner of a quilt square. They split the corner into 21°, (2x)° and 37°. Which equation finds x?

   • 2x = 21 + 37
   • 21 + 2x + 37 = 180
   • 21 + 2x + 37 = 90
   • 21 + 2x + 37 = 360
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