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AC = BC, <ACB = 40°, <AMN = 25° <CPM = ?​

AC = BC, <ACB = 40°, <AMN = 25° <CPM = ?​-example-1
User AFrieze
by
5.1k points

1 Answer

3 votes

Answer:

∠ CPM = 135°

Explanation:

given AC = BC , then Δ ABC is isosceles with base angles congruent , then

∠ ABC =
(180-40)/(2) =
(140)/(2) = 70°

the exterior angle of a triangle is equal to the sum of the 2 opposite interior angles, then

∠ AMN + ∠ BPM = ∠ ABC , that is

25° + ∠ BPM = 70° ( subtract 25° from both sides )

∠ BPM = 45°

∠ CPM and ∠ BPM are adjacent angles on a straight line and sum to 180°

∠ CPM + 45° = 180° ( subtract 45° from both sides )

∠ CPM = 135°

User Aurovrata
by
5.1k points
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