During<span> the 1960s the availability of primary sources made historical research and</span>writing<span> possible and the debate became more vigorous. Historians Herbert Feis and Gar Alperovitz raised searching questions about the </span>first use<span> of nuclear weapons and their broader political and diplomatic implications.</span>
It depends what shape it is. A triangle is equal to 180 degrees. That square at the top of the triangle means 90 degrees. 48+90=138 138-180=42. So your answer is D.
<span>B. the sight of the American flag hoisted at Fort McHenry even after being under attack for over 24 hours</span>
