Question

find the height of equilateral triangle whose side is 15cm​

Answer 1

Draw an equilateral triangle of 15 cm.

Construction method of Equilateral triangle

Step 1:- Draw a 15 cm line segment

Step 2:-Take 15 cm in combus and draw an arc on placing at the first point (first dot in the line segment)

Step 3:-Do it same at the other point

Step 4:-Then draw a equilateral triangle by joining the dot created by the two arcs to the two points on the line segments.

Mark the middle point of the 15 cm line segment

(7.5cm) Then draw a line from the middle point to the third vertex (top vertex). Then check the measure of the line which is drawn to the top vertex. That is the measure of the height of Equilateral triangle with 15 cm side.

Answer 2

$\huge\blue{ANSWER:-}$

$area = \frac{ \sqrt{3} }{4} {a}^{2} \\ \\ \frac{ \sqrt{3} }{4} \times 15 \times 15 \\ \\ = \frac{225 \sqrt{3} }{4} \\ \\ we \: know \: the \: area \: of \: triangle \\ \\ \frac{225 \sqrt{3} }{4} = \frac{1}{2} \times 15 \times h \\ \\ = \frac{225 \sqrt{3} }{4} \times 2 \times \frac{1}{15} = h \\ \\ = 7.5 \sqrt{3} \\ \\ = 13 \: \: \: \: {cm}^{2} (approx)$