In the diagram above, the value of angles b + c is
Attached Figure / Diagram
A
180o
B
90o
C
45o
D
ao
E
do
Verified Correct Answer: A.
Step-by-Step Mathematical Solution
a + c + d = 180o[sum of angles in triangle]
x = a[vertical opp. ∠s]
y + x + d = 180o[sum of ∠s in a \Delta]
y + a + d = 180o
y + a + d = a + c + d
y = c
but b + y = 180o [sum of ∠s on a straight line ]
b + c = 180o; Ans = A = 180o
Source: Myschool Past Questions Archive (Record #23780)