For the following questions answer them individually
ABC is a right angled triangle in which ∠B = 90°. If BD ⊥ AC, AB = 3 cm and BC = 4 cm, then what is the value of BD (in cm)?
Δ ABC is an equilateral triangle and D, E are midpoints of AB and AC respectively. Then the area of Δ ABC : the area of the trapezium BDEC is
If x=aCosθCosΦ, y = aCosθSinΦ and z= aSinθ, then the value of $$x^2+ y^2 + z^2$$ is