There are two situations in the first question. Consider whether you can form a triangle (the sum of two sides is greater than the third side, etc.). ), and then we can set an unknown number to calculate it. For example, let the waist be xcm and the bottom be x+6 or x-6 Yuyao for further exclusion.

The second question' The sum of the internal angles of a triangle is 180 degrees' Read the question' The height is at right angles to the waist' to form an included angle m, then the base angle = 180-m-90. Then you can find the vertex angle.

The third question. To draw an image first, you need to make an auxiliary line to connect AD. According to the fact that the two angles next to point A are right angles, it can be deduced that AC=AE=BE (the median vertical line mentioned earlier). So it is easy to find that AB is 16' BD. We can get CB according to the similarity of two triangles (I don't know if you have learned' this is simpler'), or get it from Pythagorean theorem. Let BD be x, and in the triangle △ACD, we can list the equation (according to Pythagorean theorem) that the' second question' comes from the first question.

Here is a digression: the key to doing math is to study hard. If you have time, you must think for yourself. Do you really want to skip it?

Do it again later' so that mathematical thinking can be exercised' come on'