Carcass wrote:
Attachment:
GRE In triangle PQR shown, triangles.jpg
In triangle PQR shown, triangles RPY and RYQ have areas 90 and 45 respectively. If PY = XQ = 10, what is the length of \(\overline{XY}\)?
Let,
PX = a
XY = b
YQ = c, and
RQ = H
Area of triangles RPY = \(\frac{1}{2}(a+b)H = 90\)
Area of triangles RYQ = \(\frac{1}{2}(c)H = 45\)
Now, PY = XQ = 10
i.e. a + b = 10 = b + c
Area of triangles RPY = \(\frac{1}{2}(a+b)H = \frac{1}{2}(10)H = 90\)
\(H = 18\)
Area of triangles RYQ = \(\frac{1}{2}(c)H = \frac{1}{2}(c)(18) = 45\)
c = 5
Since, b + c = 10
b = 5 = XY