Current location - Training Enrollment Network - Mathematics courses - This paper introduces in detail the answers and processes of the eighth grade mathematics books "Review Questions 19", 14 and 15 published by People's Education Press.
This paper introduces in detail the answers and processes of the eighth grade mathematics books "Review Questions 19", 14 and 15 published by People's Education Press.
14. Set the time to t.

Then PD=24-t

CQ=3t

Parallelogram:

PD=CQ

So 24-t=3t

t=6

Isosceles trapezoid:

Because BC-AD=2

So if you want to be an isosceles triangle,

The bottom is 4 longer than the top.

That is PD+4=CQ.

So 24-t+4=3t.

t=7

15. Take the midpoint g of AB, and connect EG: quadrilateral ABCD as a square ∴∠ B = 90 ∴∠ BAE +∞ BEA = 90 because AE?ef∴∠bea+∞. Because CF is the bisector of the outer corner of ∠DCB, DFC = 45, ECF = 90+45 = 135, AE=EF agrees with 0| comment.