359,391 views
45 votes
45 votes
Find the unknown measure. Round lengths to the nearest hundredth and angle measures to the nearest degree. Please help

Find the unknown measure. Round lengths to the nearest hundredth and angle measures-example-1
User Manjula Sridhar
by
2.6k points

1 Answer

16 votes
16 votes

Given:

AR=12 and AP=4.6,

Using Pythagorean theorem to find RP.


RP^2=AR^2+AP^2

Substitute AR=12 and AP=4.6, we get


RP^2=12^2+4.6^2^{}


RP^2=165.16

Taking square root on both sides, we get


RP^{}=\sqrt[]{165.16}=12.8514590611
RP=12.85

Hence the unknown length is 12.85 units.

Given that angle A=90 degrees.

Using sine law.


\frac{\text{RP}}{\sin A}=(AR)/(\sin P)=(AP)/(\sin R)

Substitute known values, we get


(12.85)/(\sin90^o)=(12)/(\sin P)=(4.6)/(\sin R)


\text{ Consider }(12.85)/(\sin90^o)=(12)/(\sin P)\text{.}
\text{Use }\sin 90^o=1.


(12.85)/(1)=(12)/(\sin P)\text{.}
\sin P=(12)/(12.85)


\sin P=0.93385214007
\text{ Use sin }69.04348449=0.93385214007


\sin P=\sin 69.04348449
P=69

Hence we get


m\angle P=69^o

Using the triangle sum property, we get


m\angle P+m\angle A+m\angle R=180^o

Substitute known values, we get


69^o+90^o+m\angle R=180^o


159^o+m\angle R=180^o


m\angle R=180^o-159^o


m\angle R=21^o

Hence we get unknown angels


m\angle R=21^o


m\angle P=69^o

The unknown length is 12.85 units.

User Ghashi
by
2.3k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.