Three to finish this crossword - 12a in right angled triangles the ratio of the side adjacent to a given angle to the side opposite C - T - - G - - T (9 letters) and 2d vertebrate blood cell that transports oxygen and carbon dioxide coloured red by haemoglobin (11 letters) E - Y - - R - C - - E, 11a any of various edible marine gastropod molluscs of the genus haliotis also known as ear shell (7 letters) A - - L - - T thanks in advance!