SME
Grade 10 Math · Problem type
Angle addition
Use this for “m∠AOB = 38° and m∠BOC = 47°. Find m∠AOC.”
Diagram
m∠AOC = 85°
This is an example. Type your own values to start a new problem.
m∠AOC
°
=
m∠AOB
°
+
m∠BOC
°
Formulas
m∠AOC = m∠AOB + m∠BOC
85 = 38 + 47
Assumptions
•
Ray OB is inside ∠AOC, so the two angles add to the whole: m∠AOB + m∠BOC = m∠AOC.
•
A bisector cuts the angle into two equal halves: then m∠AOB = m∠BOC.
Step-by-step
WE KNOW
m∠AOB = 38°, m∠BOC = 47°
FIND
m∠AOC (m∠AOC)
Step 1 · Find m∠AOC (m∠AOC)
Use m∠AOC = m∠AOB + m∠BOC
The two angles side by side add to the whole angle.
m∠AOC = 38 + 47
m∠AOC = 85°
Check
Put the numbers back in. Both sides should match.
85 = 38 + 47 ✓
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