Question

Find the area of triangle PQR.

Answer 1

Explanation:

To get the angle of QPR, we subtract 90-60=30. This proves that the triangle is a 30,60,90, as angle QRP must be 60°. To get the area, we must know the length and width. These can be derived from a known relationship within 30,60,90 triangles.

`qp = (√(3))/(2) n`

`qr = (1)/(2) n`

`pr = n`

because half of pr is 10, we can conclude that n is 20. So we plug 20 into N for QP and QR, and get values of

`qp = 5 √(3)`

`qr = 5`

Now we multiply (l*w)/2 and get:

`((5 √(3) * 5))/(2) = 21.65 \: units`