Question

From the following figure, we can say that:
$\angle a+\angle b+\angle c=4$ right angles

• A. True
• B. False

Answer 1

The correct option is A True

From the figure,
$\angle a=\angle ABC+\angle ACB$ (Exterior angle is equal to the sums of opposite interior angles)
Similarly,
$\angle b=\angle CAB+\angle BCA$
and $\angle c=\angle CBA+\angle CAB$
Add all the equations,
$\angle a+\angle b+\angle c=2(\angle ABC+\angle CBA+\angle ACB)$
$\angle a+\angle b+\angle c$ = 2(180)
$\angle a+\angle b+\angle c$ = 360
$\angle a+\angle b+\angle c$= 4 (right angles)