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

Answer Key - Grade 7 Math Worksheet - Building Confidence

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

1. 1.

   Kira sews a straight stitch line out from the square corner of a quilt patch. One part of the corner is 27°. What is the other part, angle x, in degrees?

   63
2. 2.

   Luz draws a line from the square corner of a sheet of paper for a fold-it-yourself project. One part of the corner is 58°. What is the other part, angle x, in degrees?

   32
3. 3.

   Noah runs a strip of tape out from the square corner of a box flap (the cat is very interested). One part of the corner is 71°. What is angle x, in degrees?

   19
4. 4.

   Pia opens a pair of craft scissors, and the blades cross like an X. One angle between the blades is 42°. What is angle x, next to it, in degrees?

   138
5. 5.

   Ren ties two straight kite sticks so they cross. One angle between the sticks is 103°. What is angle x, next to it on the same stick, in degrees?

   77
6. 6.

   On Tala's town map, two straight streets cross by the library. One angle at the crossing is 64°. What is angle x, next to it along the same street, in degrees?

   116
7. 7.

   Zee leans one pencil against another pencil lying flat on the desk, like a tiny ramp. The angles on each side are 125° and x. What kind of angle pair are they?

   • Complementary angles: they add to 90°, like a square corner
   • Vertical angles: they are equal
   • Supplementary angles: they add to 180°
8. 8.

   Esme cuts a straight line from the square corner of a paper square for a pinwheel. It splits the corner into a 16° angle and angle x. What kind of angle pair are they?

   • Vertical angles: they are equal
   • Supplementary angles: they add to 180°
   • Complementary angles: they add to 90°
9. 9.

   Kira pushes the art-room door open (paint smell included). The door makes a 139° angle with the straight wall, and angle x is on the other side. Which equation finds x?

   • x + 139 = 90
   • x + 139 = 360
   • x = 139
   • x + 139 = 180
10. 10.

    Milo's safety scissors cross like an X while cutting out a paper crown. Angle x is across from a 47° angle. Which equation finds x?

    • x = 47
    • x + 47 = 360
    • x + 47 = 180
    • x + 47 = 90