2. Points A, B and C are all on the circumference of the circle. o
represents the centre.
DA and DB are tangents to the
circle. Angle BDO = 31
Work out the size of angle.

Question

Points A, B and C are all on the

circumference of the circle. O represents the centre. DA and DB are tangents to the circle. Angle BDO = 31°

Work out the size of angle x

62°

Step-by-step explanation:

To solve for the above question, we would be using circle theorems.

Step 1

Angle OBD = 90° This is because a radius and a tangent meet at 90°

Step 2

The sum of Angles in a triangle = 180°

180° = Angle OBD + Angle BDO + Angle BOD

180° = 90° + 31° + Angle BOD

Angle BOD = 180° - (90° + 31°)

= 180° - 121°

Angle BOD = 59°

Step 3

Angle BOD = Angle AOD because they are congruent ,therefore, Angle AOD = 59°

Step 4

The sum of angles of a straight line = 180°

Angle BOD, Angle AOD and Angle x are angles on a straight line

Hence,

180° = Angle BOD + Angle AOD + Angle x

180° = 59° + 59° + x

x = 180° - ( 59 + 59)°

x = 180° - 118°

x = 62°

Therefore Angle x = 62°

-12 > a

step-by-step explanation:

-11 > 1 + a

subtract 1 from each side

-11-1 > 1-1+a

-12 > a

51840000 cm 2

step-by-step explanation: