Problem:
In the adjoining figure, CDE is an equilateral triangle and ABCD and DEFG are squares. The measure of β GDA is
Answer Choices:
A. 90β
B. 105β
C. 120β
D. 135β
E. 150β
Solution:
The measures of angles β ADC,β CDE and β EDG are 90β,60β and 90β, respectively. Hence the measure of β GDA is
360ββ(90β+60β+90β)=120β.