Two corners of an isosceles triangle are at (4 ,3 )(4,3) and (9 ,3 )(9,3). If the triangle's area is 64 64, what are the lengths of the triangle's sides?

1 Answer
Aug 4, 2017

Length of sides of triangle are 5, 25.72(2dp) ,25.72(2dp) 5,25.72(2dp),25.72(2dp) unit

Explanation:

The base of the isosceles triangle,

b=sqrt( (x_1-x_2)^2+(y_1-y_2)^2) = sqrt( (4-9)^2+(3-3)^2) b=(x1x2)2+(y1y2)2=(49)2+(33)2

= sqrt25 = 5 =25=5 unit .

The area of the isosceles triangle is A_t = 1/2 * b *h =1/2*5 *h At=12bh=125h

A_t=64 :. h = (2* A_t )/b = (2*64)/5=128/5= 25.6 unit.

Where h is the altitude of triangle.

The legs of the isosceles triangle are l_1=l_2= sqrt(h^2+(b/2)^2)=sqrt(25.6^2+(5/2)^2) ~~25.72(2dp) unit

Hence the length of three sides of triangle are

5, 25.72(2dp) ,25.72(2dp) unit [Ans]