Question

The base of an isosceles triangle is 7 cm longer than the legs. Find the legs if the perimeter of the triangle is 43 cm.

Answer 1

121

Explanation:

legs are x but base is x+7

x+x+x+7 is perimeter = 43

3x+7=43

3x=36

x=12

Answer 2

An isosceles triangle is a triangle that has one pair of equal sides. The Formula in finding the perimeter of a triangle is PΔ=S₁+S₂+S₃. Since two legs are missing, and the given are the base and perimeter, we will use the formula : S₁+S₂ = PΔ-S₃, where: S₁+S₂ are the legs and S₃ is the base.
Substitute values:
S₁+S₂ = 43cm - 7 cm
= 36 cm
since S₁ and S₂ are equal, divide 36cm by 2. Therefore S₁ and S₂ measures 18cm.
Check: PΔ=S₁+S₂+S₃
= 18cm + 18 cm + 7cm
= 43cm