.present_txt { position:relative; width:100%; } /*전체크기*/

.btn1        { left:74.5%; bottom:19.2%; width:15%; height:4.2%; }

.btn_golink{display:block; position:absolute;}

.btn_golink img{width:100%; height:100%;}

<div class="present_txt">

   <img src="전체이미지">

    <div class="btn_golink btn1" alt="이미지위 버튼클릭 지정함.">[클릭]</div>

</div>