Question

10. there is a circle with centre O and diameter AB.
(1) Find angle APB.
(ii) If A = angle 60°, find angle B.
(iii) IF AP = 5 cm and PB = 12 cm, find AB and radius of
circle.
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Answer 1

As AB is diameter, any angle in semicircle will be 90 degree

therefore, angle APB =90 degree.

in triangle APB,

Measure of angle A+measure of angle B+measure of angle P=180 degree.

therefore,

60+measure of angle B+90=180

150+measure of angle B=180

measure of angle B=180-150

therefore, measure of angle B=30 degree.

5,12and 13 is Pythagorean triplet.

therefore,AB=13.

radius=2 X diameter.

therefore, radius of circle=6.5 cm

I hope it helps you

Answer 2

Answer:

the answer are below

Step-by-step explanation:

1)90°

as, angle inside a semicircle touching the arc and one side is the diameter is an right angle

2)30°

as,sum of all angles of an triangle is equal to 180°

3)13cm

by pythagoras theorem