#1**0 **

In the triangle on the left, you have a 90^{o} right angle and a 48^{o} angle

The total of the interior angles of a triange is 180^{o} so the third angle is 42^{o}

Across from the 42^{o} angle is its vertical angle which is equal so it's also 42^{o}

So the two angles we know in the triangle on the right total (42^{o} + 66^{o}) = 108^{o}

That means angle M is (180^{o} – 108^{o}) = **72 ^{o}**

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Guest Apr 2, 2021