Classes
Class 9Class 10First YearSecond Year
$3. \mathrm{ABC} is a triangle in which m \angle \mathrm{A}=25^{\circ} m \angle \mathrm{B}=45^{\circ} and \overline{\mathrm{CD}} \perp \overline{\mathrm{AB}} . Prove that \triangle \mathrm{DBC} is an isosceles \Delta .$  $4. Find the value of unknowns for the given congruent triangles.$  $2. From a point on the line bisector of an angle perpendiculars are drawn to the arms of the angle. Prove that these perpendiculars are equal in measure.$  $1. \mathrm{ABC} is an isosceles triangle. \mathrm{D} is the mid-point of base \overline{\mathrm{BC}} . Prove that \overline{\mathrm{AD}} bisects \angle \mathrm{A} and \overrightarrow{\mathrm{AD}} \perp \overrightarrow{\mathrm{BC}} .$  $2. Prove that a point which is equidistant from the end points of a line segment is on the right bisector of the line segment.$  $3. Fill in the blanks to make the sentences true sentences:(vi) The sum of the measures of acute angle of a right triangle is$  $(iv) How many acute angles are there in an acute angled triangle?(a) 1(b) 2(c) 3(d) not more than 2 .$  