In a right angled triangle ∠ABC, ABC = 90°, AB = 3cm., BC = 4cm. and the perpendicular BD on the side AC from the point B which meets the side AC at the point D. Let us determine the length of BD.

In ΔABC, if AB = (2a-1)cm. AC = 2 √2acm. And BC = (2a + 1)cm., then let us write the value of ∠BAC.

In the adjoining figure, the point O is situated within the triangle PQR in such a way that ∠POQ = 90°, OP = 6cm. and OQ = 8cm. If PR = 24cm. and ∠QPR = 90°, then let us write the length of QR.

The point O is situated within the rectangular figure ABCD in such a way that OB = 6 cm., OD = 8cm. and OA = 5cm. Let us determine the length of OC.

In the triangle ABC the perpendicular AD from the point A on the side BC meets the side BC at the point D. If BD = 8cm, DC = 2cm. and AD = 4cm., then let us write the measure of ∠BAC.