C-10-Q063mediumsingle_mcq

The horizontal distance from the foot of the wall to the foot of the ladder is—

a $9\sqrt{2}$ m
b $18\sqrt{2}$ m
c $9$ m
d $18$ m

ব্যাখ্যা

In a $45^\circ$ right triangle the horizontal distance equals the vertical height, so it is also $18\cos 45^\circ=9\sqrt{2}$ m. The two legs are equal because the base angles are both $45^\circ$ .

এই অধ্যায়ের আরও প্রশ্ন

C-10-Q064In a –– right triangle, the two legs are—
C-10-Q065The stick contacts the tree at m above the ground; the depression angle at the contact is . By alternate angle
C-10-Q066From right with stick as hypotenuse, equals—
C-10-Q067Therefore equals—
C-10-Q068The length of the stick in Example 4 is—
C-10-Q069The reasoning that the depression angle at equals at uses the fact that the two horizontal lines at and at are
C-10-Q070Angle of depression from a higher point and angle of elevation from a lower point form—
C-10-Q071Building height , , with . Then equals—
C-10-Q072From the equation , we get
C-10-Q073Moving back m to point gives elevation , so equals—

Chapter 10: Distance and Elevation — সব প্রশ্ন দেখুন (160টি) →

The horizontal distance from the foot of the wall to the foot of the ladder is—

9\sqrt{2}

18\sqrt{2}

9

18

ব্যাখ্যা

In a $45^\circ$ right triangle the horizontal distance equals the vertical height, so it is also $18\cos 45^\circ=9\sqrt{2}$ m. The two legs are equal because the base angles are both $45^\circ$ .