An extensible tape member is provided for measuring a voluntary angle or for measuring length of an object. The extensible tape member may be pulled out of the housing of an electronic combined protractor and calculator in measuring either angle or length. A rotatory reel which accomodates and stores the extensible tape member therein is rotated in unison with the extension of the extensible tape member from its housing. A photo sensor is provided for detecting rotation of the rotatory reel and for providing counting signals corresponding to the rotation. One of two indexes is arranged on a frame of the rotatory reel while the other of the indexes is positioned on the lower half of the housing of the electronic combined protractor and calculator. When measuring angle, the two indexes should be attached to two lines defining the angle to be measured, respectively. One of the indexes is rotatably driven along with the extension of the extensible tape member, whereby the rotatory reel is rotated in accordance with a degree of the angle to be measured. The counting signals are introduced into a control circuit to determine the degree of the angle. When measuring the length, the extensible tape member is adjusted in length to correspond to the length of the object to be measured while extending out of the housing. The rotation of the rotatory reel is utilized for determining the length of the object in almost the same manner as for the angular measurement.