We are given a circle with center T. $PL$ and $KM$ are diameters of the circle. We need to find the measure of arc $PJ$. From the diagram, we are given that $m\angle MTN = 48^\circ$, $m\angle NTP = 42^\circ$, $m\angle JTK = 32^\circ$, and $m\angle KTL = 90^\circ$.

GeometryCircleAnglesArcsDiametersCentral Angle
2025/5/4

1. Problem Description

We are given a circle with center T. PLPL and KMKM are diameters of the circle. We need to find the measure of arc PJPJ. From the diagram, we are given that mMTN=48m\angle MTN = 48^\circ, mNTP=42m\angle NTP = 42^\circ, mJTK=32m\angle JTK = 32^\circ, and mKTL=90m\angle KTL = 90^\circ.

2. Solution Steps

Since PLPL is a diameter, mPTL=180m\angle PTL = 180^\circ. Also, mPTJ=mPTK+mJTKm\angle PTJ = m\angle PTK + m\angle JTK.
Since the measure of an arc is equal to the measure of its central angle, we need to find the measure of the central angle PTJ\angle PTJ.
First, we find mMTPm\angle MTP.
mMTL+mLTP=180m\angle MTL + m\angle LTP = 180^\circ (Since PLPL is a straight line).
Also, mMTN+mNTK=180mMTPm\angle MTN + m\angle NTK = 180^\circ - m\angle MTP.
Since KMKM is a diameter, mKTM=180m\angle KTM = 180^\circ.
mKTM=mKTL+mMTL=90+mMTL=180m\angle KTM = m\angle KTL + m\angle MTL = 90^\circ + m\angle MTL = 180^\circ.
From this, we get mMTL=18090=90m\angle MTL = 180^\circ - 90^\circ = 90^\circ.
So, mMTP=180(mNTP+mNTJ)m\angle MTP = 180^\circ - (m\angle NTP + m\angle NTJ)
mPTK+mKTL=180(mMTP)m\angle PTK + m\angle KTL = 180^\circ - (m\angle MTP)
We also know that the sum of the angles around the center T is 360360^\circ.
mMTN+mNTP+mPTK+mKTL+mLTM=360m\angle MTN + m\angle NTP + m\angle PTK + m\angle KTL + m\angle LTM = 360^\circ.
48+42+mPTK+90+mLTM=36048^\circ + 42^\circ + m\angle PTK + 90^\circ + m\angle LTM = 360^\circ.
Also, mMTL=90m\angle MTL = 90^\circ (because KM is a diameter and angle KTL is a right angle)
Since PL is a straight line, mPTL=180m\angle PTL = 180^\circ.
Therefore mPTL=mPTK+mKTL=mPTK+90=180m\angle PTL = m\angle PTK + m\angle KTL = m\angle PTK + 90^\circ = 180^\circ.
So mPTK=18090=90m\angle PTK = 180^\circ - 90^\circ = 90^\circ.
Then, mPTJ=mPTK+mJTK=90+32=122m\angle PTJ = m\angle PTK + m\angle JTK = 90^\circ + 32^\circ = 122^\circ.
Since the measure of an arc equals the measure of its central angle, mPJ^=mPTJ=122m\widehat{PJ} = m\angle PTJ = 122^\circ.

3. Final Answer

122

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