We present the absolute properties of the double-lined eclipsing binary KIC 6206751 exhibiting multiperiodic pulsations .
The { \it Kepler } light curve of this system was simultaneously solved with the radial-velocity data given by Matson et al .
( 2017 ) .
The results indicate that the binary star is a short-period semi-detached system with fundamental parameters of M _ { 1 } = 1.66 \pm 0.04 M _ { \odot } , M _ { 2 } = 0.215 \pm 0.006 M _ { \odot } , R _ { 1 } = 1.53 \pm 0.02 R _ { \odot } , R _ { 2 } = 1.33 \pm 0.02 R _ { \odot } , L _ { 1 } = 5.0 \pm 0.6 L _ { \odot } , and L _ { 2 } = 0.96 \pm 0.09 L _ { \odot } .
We applied multiple frequency analyses to the eclipse-subtracted light residuals and detected the 42 frequencies below 2.5 d ^ { -1 } .
Among these , three independent frequencies of f _ { 2 } , f _ { 3 } , and f _ { 4 } can be identified as high-order ( 38 \leq n \leq 40 ) low-degree ( \ell = 2 ) gravity-mode oscillations , whereas the other frequencies may be orbital harmonics and combination terms .
The ratios between the orbital frequency and the pulsation frequencies are f _ { orb } : f _ { 2 - 4 } \simeq 2:3 , which implies that the \gamma Dor pulsations of the detached primary star may be excited by the tidal interaction of the secondary companion .
The short orbital period , and the low mass ratio and M _ { 2 } demonstrate that KIC 6206751 is an R CMa-type star , which is most likely evolving into an EL CVn star .
Of seven well-studied R CMa-type stars , our program target is the only eclipsing binary with a \gamma Dor pulsating component .