In ∆PQR measure of angle Q is $$90^\circ$$. If $$ cosec P = \frac{17}{15}$$, and PQ = 0.8cm, then what is the length (in cm) of side QR?

Given : $$\cosec P$$ = $$\frac{17}{15}$$

Also, $$\cosec P=\frac{PR}{QR}=\frac{17}{15}$$

Let PR = $$17x$$ cm and QR = $$15x$$ cm

Thus, in $$\triangle$$ PQR, => $$(PQ)^2=(PR)^2-(QR)^2$$

=> $$(PQ)^2=(17x)^2-(15x)^2$$

=> $$(PQ)^2=289x^2-225x^2=64x^2$$

=> $$PQ=\sqrt{64x^2}=8x$$ cm

According to ques, => $$8x=0.8$$

=> $$x=\frac{0.8}{8}=\frac{1}{10}$$

$$\therefore$$ QR = $$15\times\frac{1}{10}=1.5$$ cm

=> Ans - (D)