If four angles of a pentagon measure 108°, 115°, 89° and 102°, find the measure of the fifth angle. 54° 540° 306° 126°

126 because a pentagon equals 540 so if u add up all the side and subtract by what u get which is 414 u get 126

the law of definite proportions states samples of a compound will always contain the same proportion of elements by mass. in other words, a given compound will always contain the same elements in the same proportions by mass.the law of multiple proportions states when two elements combine with each other to form more than one compound, then the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers.