Two corners of an isosceles triangle are at (2 ,9 )(2,9) and (8 ,3 )(8,3). If the triangle's area is 9 9, what are the lengths of the triangle's sides?

1 Answer
Dec 23, 2017

The length of three sides of triangle are 8.49 ,4.74 , 4.748.49,4.74,4.74 unit

Explanation:

Base of the isocelles triangle is

B= sqrt((x_1-x_2)^2+(y_1-y_2)^2)) = sqrt((2-8)^2+(9-3)^2)B=(x1x2)2+(y1y2)2)=(28)2+(93)2

=sqrt(36+36)=sqrt72 ~~8.49(2dp)=36+36=728.49(2dp)unit

We know area of triangle is A_t =1/2*B*HAt=12BH Where HH

is altitude. :.9=1/2*8.49*H or H= 18/8.49~~2.12(2dp)unit

Legs are L = sqrt(H^2+(B/2)^2)= sqrt( 2.12^2+(8.49/2)^2)

=4.74(2dp)unit.

The length of three sides of triangle are 8.49 ,4.74 , 4.74 unit [Ans]