Answer:
The length of KS is 25 units and the length of KP is 17 units.
Explanation:
Given information: KPST is a trapezoid, KP=ST, MN is a mid segment, MN=20, h=15, PS:KT=3:7 .
Since two sides of the trapezoid are equal therefore it is an isosceles trapezoid.
The midsegment of a trapezoid is a line segment which connects the midpoints of the non-parallel sides.
The length of mid segment is average of length of parallel lines. The length of mid segment is 20.
It is given that PS:KT=3:7. Let the length of sides be 3x and 7x respectively.
![(3x+7x)/(2)=20](https://img.qammunity.org/2019/formulas/mathematics/middle-school/k49y1fucj4nbwyu1itbwrogkuc2nxv1uow.png)
![(10x)/(2)=20](https://img.qammunity.org/2019/formulas/mathematics/middle-school/2pm1p27f71x12ve3xi3h01sgzkihz28ocl.png)
![5x=20](https://img.qammunity.org/2019/formulas/mathematics/middle-school/a1vj1fa12k8ejcz3akwvo92l479hjwg2ei.png)
![x=4](https://img.qammunity.org/2019/formulas/mathematics/middle-school/i23qk0uwhi1ehnolmndlq35wd5e9sddv2g.png)
The value of 3x and 7x are 12 and 28 respectively. So, the length of sides PS and KT is 12 and 28 respectively.
Use pythagoras in triangle AKP.
![AK^2+AP^2=KP^2](https://img.qammunity.org/2019/formulas/mathematics/middle-school/by1zdbawirestklzusja1tjqngrz8eri2k.png)
![(8)^2+(15)^2=KP^2](https://img.qammunity.org/2019/formulas/mathematics/middle-school/v4m0nksnkox3uirbcy91s3w096ioeau82d.png)
![√(64+225)=KP](https://img.qammunity.org/2019/formulas/mathematics/middle-school/vgqw4ir372p4ns7l6fvia5g6dxeqf9r7g4.png)
tex]\sqrt{289}=KP[/tex]
![17=KP](https://img.qammunity.org/2019/formulas/mathematics/middle-school/ythg1t56qbsgmujgcq8rewit8v50czzbk3.png)
Use pythagoras in triangle BKS.
![BK^2+BS^2=KS^2](https://img.qammunity.org/2019/formulas/mathematics/middle-school/4bsb7gq54p9hhki47mktlch2y46bh0e0cl.png)
![(20)^2+(15)^2=KS^2](https://img.qammunity.org/2019/formulas/mathematics/middle-school/4lojsp49lbg1hvtszy547uhoisez9smjk7.png)
![√(400+225)=KS](https://img.qammunity.org/2019/formulas/mathematics/middle-school/vb9n1ub0c636x69xjzkb19s4liiyl479vb.png)
tex]\sqrt{625}=KS[/tex]
![KS=25](https://img.qammunity.org/2019/formulas/mathematics/middle-school/ouom2af8vug9dx6f3pg7e1ashszwihnezi.png)
Therefore length of KS is 25 units and the length of KP is 17 units.