Rules for a 30-60-90 right triangle: hyp = 2 * short leg Long leg = sqrt(3) * short leg Given: hyp = 7 7 = 2*short leg divide both sides by 2 7/2 = short leg long leg = sqrt(3) * short leg long leg = sqrt(3) * (7/2) long leg = 6.06 P= s1 + s2 + s3 P = 7 + 3.5 + 6.06 P = 16.56 units (Decimal approximation) P = 10.5 + 3.5sqrt(3) units (Exact value)