##### Across

**2.**a line that passes through two lines in the same plane at two distinct points in the geometry**6.**instrument used for meaning angles with a rotating telescope**9.**when 2 figures are in equal shape and size**10.**U-shaped curve that is drawn for a quadratic function**11.**if the lines are parallel**12.**any angle greater than 90°**14.**an alphabet or term that represents an unknown number or unknown value or unknown quantity**15.**a resultant number when one number is divided by the other number**17.**a number or quantity placed with a variable**19.**those angles that sum up to 180 degrees

##### Down

**1.**father of mathematics**3.**invented zero**4.**When the sum of two angles is equal to 90 degrees**5.**when 2 figures shape is same, but size is proportional**7.**if the lines intersect at a point**8.**longest side in a right-angled triangle**9.**A constant is a value or number that never changes in expression**13.**An angle which is measuring less than 90 degrees**16.**A line that touches the circle at a single point**18.**triangle that has at least two sides of equal length