Respuesta :

Answer:

A = 210 cm²

Step-by-step explanation:

Perimeter of the triangle = the sum of the sides of the triangle.

70 = (3x - 1) + (4x + 1) + (3x)

70 = 10x  

7 = x     The length of the sides of the triangle are 3x - 1 = 20;  4x + 1 = 29 and                

             3x = 21.

 Looking at the given information, this triangle is a special type of triangle because the area of a triangle is Area = 1/2 bh and you do not know which side is the base and height of the triangle.

Trying a² + b² = c² to see if it is a right triangle.   20² + 21² = 29 ² ; yes it is a right triangle and now we know that the base and height is 20 and 21.   The longest side is the hypotenuse in a right triangle

A = 1/2bh

A = 1/2 (20)(21)

A = 10 · 21

A = 210 cm²