Angle Addition Postulate
Activity
Drag the points A, B, C and D in the sketch below
Determine whether the following statement is always, sometimes, or never true.
D is in the interior of ∠ABC
Determine whether the following statement is always, sometimes, or never
m∠ABD + m∠DBC = m∠ABC
If D is in the interior of ∠ABC , m∠ABC=123° and m∠ABD=55°. Find m∠CBD
If m∠ABD=130° and m∠ABC=50°. Find m∠DBC