61 Un quadrato e un rettangolo sono isoperime- trici. L'altezza del rettangolo misura 25 cm e la base supera l'altezza di 8 cm . Calcola la misura del lato del quadrato. [ 29 cm\( ] \)

EXERCISE 15.1 (in the figure, seg OP \( \perp \mathrm{seg} S T \). Chord LM \( \| \) chord ST. O is the centre of the circle. \( \mathrm{ON}=6 \mathrm{~cm}, \mathrm{LM}=16 \mathrm{~cm} \). Find the length of the longest chord that can be drawn in the circle. (2018) \( \begin{array}{llll}\text { (1) } 32 \mathrm{~cm} & \text { (2) } 20 \mathrm{~cm} & \text { (3) } 12 \mathrm{~cm} & \text { (4) } 22 \mathrm{~cm}\end{array} \)

สระน้ำรูปวงกลมมีรัศมียาว 24.5 เมตร ถ้าเดินรอบสระน้ำ 2 รอบ จะได้ระยะทางกี่เมตร \( \left(\pi \approx \frac{22}{7}\right) \)

A ball bounces \( \frac{1}{2} \) of its previous height on each bounce. Find the total distance covered by the ball, until it comes to rest, if it is dropped from a height of 20 metres.

Find the equation of line perpendicular to \( 5 x-3 y+4=0 \) that passes through the point \( (-4,1) \).

What results when a plane is parallel to the axis of a double-napped cone and passes through the vertex? point parabola two intersecting lines a single line