The perimeter of an isosceles triangle is 90 and the lateral side is 25. Find the area of the triangle.
| February 14, 2021 | education
1. A, B, C – the vertices of the triangle. P is the perimeter. p – 1/2 of the perimeter. S – area.
2. P = AC + AB + BC = 90 units.
BC = AB, since the triangle is isosceles.
AC = 90 – 25 – 25 = 40 units.
3. Calculate the area of a triangle using Heron’s theorem:
S = √p (p – AC) (p – AB) (p – BC). p = 90: 2 = 45 units.
S = √p (p – AC) (p – AB) (p – BC) = √45 x 5 x 20 x 20 = √225 x 20 x 20 = 15 x 20 = 300 units of measurement².
Answer: S = 300 units of measure².
One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.
