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

Answer Key - Grade 7 Math Worksheet

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

1. 1.

   Two bike paths leave a straight trail at the same point near Pia's school. Along the trail the angles are 33°, x and 41°. What is x, in degrees?

   106
2. 2.

   Ari cuts a pizza with two straight cuts that cross. A short cut from the middle splits one angle into 44° and 39°. Angle x is across from that whole angle. What is x?

   83
3. 3.

   Bo's kite sticks cross, and the tail string ties on at the crossing. It splits one angle into 52° and 61°. Angle x is across from that whole angle. What is x, in degrees?

   113
4. 4.

   Jun swings the gym door open for the relay race. The angles on each side of the door are supplementary: 84° and (3x)°. What is x?

   32
5. 5.

   Luz sticks a paper chain out from the square corner of a window. It splits the corner into complementary angles of 22° and (4x)°. What is x?

   17
6. 6.

   Zee's kite sticks cross like an X. The (x + 25)° angle is across from a 94° angle. Which equation finds x?

   • x + 25 + 94 = 360
   • x + 25 + 94 = 90
   • x + 25 + 94 = 180
   • x + 25 = 94
7. 7.

   Ari draws a line out from the square corner of a birthday-card envelope. It splits the corner into 31° and (3x)°. Which equation finds x?

   • 3x + 31 = 180
   • 3x + 31 = 90
   • 3x = 31
   • 3x + 31 = 360
8. 8.

   Kira cuts a round pizza into three slices from the center (one slice is clearly the biggest). Two slice angles are 85° and 70°. What is the third angle, x, in degrees?

   205
9. 9.

   Luz paints three spokes of a bike wheel bright colors. The painted spokes make angles of 62°, 104° and x around the hub. What is x, in degrees?

   194
10. 10.

    Milo cuts a birthday cake into three pieces from the center. Two of the angles at the center are 118° and 47°. What is the third angle, x, in degrees?

    195