The problem asks to find the size of the angle $m$ in the given diagram. We know that angles around a point sum to $360^\circ$. However, since the diagram shows only half of the angles around the point, and we have straight lines going through the point, the sum of the angles shown must be half of $360^\circ$, which is $180^\circ$.

GeometryAnglesGeometryStraight LinesAngle SumDiagram
2025/5/5

1. Problem Description

The problem asks to find the size of the angle mm in the given diagram. We know that angles around a point sum to 360360^\circ. However, since the diagram shows only half of the angles around the point, and we have straight lines going through the point, the sum of the angles shown must be half of 360360^\circ, which is 180180^\circ.

2. Solution Steps

The sum of the angles in a straight line is 180180^\circ. Therefore, the sum of the angles shown in the figure should be 180180^\circ. We have the angles 1313^\circ, 2424^\circ, 1515^\circ, and mm.
Thus, we have
13+24+15+m=18013 + 24 + 15 + m = 180
52+m=18052 + m = 180
m=18052m = 180 - 52
m=128m = 128

3. Final Answer

The size of angle mm is 128128^\circ.

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