13.The perimeter of an isosceles triangle is 14. If thelength of the base of the triangle is one less thanthe length of each leg, find the length of a leg.

Answer:5 unitsStep-by-step explanation:An isosceles triangle is a triangle with two legs that have the same length. The perimeter of a triangle is the sum of the lengths of all sides of the triangle. Now taking this into account, we know that:2L + B = 14 unitsWhere:L is the measure of one legB is the measure of the baseSince two legs are the same and the base is 1 less, this means the measure of each leg would be:B = L -1Now we have two equations:2L + B = 14 unitsB = L- 1We plug one equation into the other and make 1 equation:2L + (L-1) = 14 unitsGet rid of the parentheses:2L + L - 1 = 14 Combine like terms:3L - 1 = 14 Add 1 to both sides of the equation:3L - 1 + 1 = 14 + 13L = 15Divide both sides by 3:3L/3 = 15/3L = 5So the length of a leg is 5 unitsLet's check!B = L - 1B = 5 - 1B = 4Then we use that to solve for the perimeter:2L + B 2(5) + 410 + 4 = 14