Let P be an interior point of triangle ABC. Let Q and R be the reflections of P in AB and AC, respectively. If Q,A,R are collinear then `/_A` equals

Let P be an interior point of a triangle ABC , Let Q and R be the reflections of P in AB and AC , respectively if Q .A , R are collinear then angle A equals -

If in a triangle AB=a,AC=b and D,E are the mid-points of AB and AC respectively, then DE is equal to

Let C_1 and C_2 be respectively, the parabolas x^2=y=-1 and y^2=x-1 Let P be any point on C_1 and Q be any point on C_2 . Let P_1 and Q_1 be the refelections of P and Q, respectively with respect to the line y=x. If the point p(pi,pi^2+1) and Q(mu^2+1,mu) then P_1 and Q_1 are

In triangleABC , P,Q and R are the midpoints of AB, BC and CA respectively. If ar(ABC)=32 cm^2 , then ar(PQR)= ____ cm^2

In triangleABC , P, Q and R are the midpoints of AB, BC and CA respectively . If ar(PBQR)=36 cm^2 , then ar(ABC)=____ cm^2

In triangleABC , P, Q and R are the midpoints of AB, BC and CA respectively . If ar(ABC)=____40 cm^2 , then ar(PBCR)= ____ cm^2

In the given figure, sides AB and AC of triangle ABC are extended to points P and Q respectively. Also, angle PBC lt angle QCB . Show that AC gt AB

ABC is a right triangle right angled at B. Let D and E be any points on AB and BC respectively. Prove that AE^(2) + CD^(2) = AC^(2) + DE^(2) .

In Delta ABC , P, Q and R are the midpoints of AB, BC and CA respectively. If PQ = 5 cm, QR = 8 cm and RP = 6.5 cm, find the perimeter of Delta ABC .

Find the area of the triangle formed by the points P(-1.5, 3), Q(6,-2) and R(-3, 4).