What is the role of a plane mirror and a glass sheet in a solar cooker?

(N/A) $1$. The plane mirror acts as a reflector that reflects sunlight into the box of the solar cooker,thereby increasing the intensity of solar radiation falling on it.
$2$. The glass sheet allows short-wavelength solar radiation to enter the box but prevents long-wavelength infrared radiation (heat) from escaping,thus trapping the heat inside. This phenomenon is known as the greenhouse effect,which helps in raising the temperature inside the cooker.