Missing angles with letters: straight lines, corners and crossing lines

Answer Key - Grade 8 Math Worksheet - Challenge Me

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

1. 1.

   Noah folds a paper strip so that three angles, (x + 5)°, (2x + 10)° and (3x + 15)°, sit side by side along its straight edge. How many degrees is the largest angle?

   90
2. 2.

   Pia draws two rays from one point on a straight line on paper, making three angles: (2x)°, (3x + 10)° and (4x + 8)°. How many degrees is the largest angle?

   80
3. 3.

   In Ren's paper sketch, three paths leave one point on a straight road, making angles of (x + 14)°, (2x − 5)° and (5x − 5)°. How many degrees is the largest angle?

   105
4. 4.

   Tala opens two doors from one hinge line against a straight wall, making angles of (3x + 6)°, (2x + 14)° and (4x − 2)°. How many degrees is the largest angle?

   70
5. 5.

   Ari draws a square corner on paper and splits it with one ray. One part is 10° less than three times the other. How many degrees is the bigger part?

   65
6. 6.

   Bo's ramp board makes two angles with the flat ground. One is 5° more than four times the other. How many degrees is the bigger angle?

   145
7. 7.

   Jun's scissor blades cross. Two angles side by side are (4x + 10)° and (2x + 20)°. How many degrees is the angle across from the (2x + 20)° angle?

   70
8. 8.

   Kira draws two roads crossing on paper. Two angles side by side are (5x + 15)° and (3x + 5)°. How many degrees is the angle across from the (3x + 5)° angle?

   65
9. 9.

   Luz draws two lines crossing on a clock face. Side by side are (3x + 24)° and (2x + 6)°. How many degrees is the angle across from the (2x + 6)° angle?

   66
10. 10.

    Two paper creases cross on Milo's sheet. Side by side are (6x − 6)° and (2x + 26)°. How many degrees is the angle across from the (2x + 26)° angle?

    66