EXERCISE 14.1 Step 3 7 1. Draw a circle of radius 3.2 cm. 2. With the same centre 0, draw two circles of radii 4 cm and 2.5 cm. T compass A and s 3. Draw a circle and any two of its diameters. If you join the ends of these diameters, your answer? Step what is the figure obtained? What figure is obtained if the diameters are perpendicular to each other? How do you check 4. Draw any circle and mark points A, B and C such that (a) A is on the circle. (b) B is in the interior of the circle. (c) C is in the exterior of the circle. · Let A, B be the centres of two circles of equal radii; draw them so that each one of them passes through the centre of the other. Let them intersect at C and D. Examine whether AB and CD are at right angles.
Answers
Step-by-step explanation:
Let us represent the two (first and second digit respectively) digits that make up the number with (X) and (Y)
The two-digit number, in real sense, will be 10X + Y (Since the value of the first digit is in Tens).
Since the sum of the digits is 7, we have:
X + Y = 7 ————————————- (1)
Reversing the digits, we have: 10Y + X
Reversing the digits increases the number by 9. We have:
10Y + X = 10X + Y + 9 ———————-(2)
From equation (1), we have:
X = (7 - Y) ————————————(3)
Let us substitute (7 - Y) for X in equation (2):
10Y + 7 - Y = 10(7 - Y) + Y + 9
9Y + 7 = 70 - 10Y + Y + 9
9Y + 7 = 79 - 9Y
9Y + 9Y = 79 - 7
18Y = 72, Y = 72/18
Y = 4
Let us substitute (4) for Y in equation (3):
X = 7 - 4
X = 3.
Putting the two digits together, the two-digit number is:
34.