Help pls i don’t get it

A = 22.5 m²

Step-by-step explanation:

longest side length

b = √((-7 + 4)² + (-1 - 8)²) = √90

other sides

a = √((-1 + 7)² + (2 + 1)²) = √45

height

h = √((√45)² - (½√90)²) = √22.5

Area of triangle

A = ½bh = ½√90√22.5 = 22.5 m²

a little math shows that this triangle is a tilted half of a square with sides √45

3

step-by-step explanation:

the sum of the lengths of any two sides of a triangle is greater than the length of the third side. if you take the three sides of a triangle and add them in pairs, the sum is greater than (not equal to) the third side. if that is not true, then it is not possible to construct a triangle with the given side lengths.

step-by-step explanation: