Browse · MATH
Printjmc
prealgebra intermediate
Problem
Bob placed three regular pentagons together at a vertex, thinking he might be able to form a tessellation. However, they left a gap. What is the number of degrees in the measure indicated? 
Solution
The angles of a pentagon sum to degrees, so each angle of a regular pentagon is . Therefore, three of these angles sum to , which means the indicated angle measures .
Final answer
36^\circ