Nửa chu vi tam giác:

\(\frac{\left(\right. 10 + 17 + 21 \left.\right)}{2}=24\left(\operatorname{cm}\right.\left.\right)\)

Diện tích tam giác:

\(S=\sqrt{24. \left(\right. 24 - 10 \left.\right) . \left(\right. 24 - 17 \left.\right) . \left(\right. 24 - 21 \left.\right)}=84\left(\right.cm^2\left.\right)\)

Nửa chu vi tam giác:

\(\frac{\left(\right. 10 + 17 + 21 \left.\right)}{2}=24\left(\operatorname{cm}\right.\left.\right)\)

Diện tích tam giác:

\(S=\sqrt{24. \left(\right. 24 - 10 \left.\right) . \left(\right. 24 - 17 \left.\right) . \left(\right. 24 - 21 \left.\right)}=84\left(\right.cm^2\left.\right)\)

Nửa chu vi tam giác:

\(\frac{\left(\right. 10 + 17 + 21 \left.\right)}{2}=24\left(\operatorname{cm}\right.\left.\right)\)

Diện tích tam giác:

\(S=\sqrt{24. \left(\right. 24 - 10 \left.\right) . \left(\right. 24 - 17 \left.\right) . \left(\right. 24 - 21 \left.\right)}=84\left(\right.cm^2\left.\right)\)

Nửa chu vi tam giác:

\(\frac{\left(\right. 10 + 17 + 21 \left.\right)}{2}=24\left(\operatorname{cm}\right.\left.\right)\)

Diện tích tam giác:

\(S=\sqrt{24. \left(\right. 24 - 10 \left.\right) . \left(\right. 24 - 17 \left.\right) . \left(\right. 24 - 21 \left.\right)}=84\left(\right.cm^2\left.\right)\)

Nửa chu vi tam giác:

\(\frac{\left(\right. 10 + 17 + 21 \left.\right)}{2}=24\left(\operatorname{cm}\right.\left.\right)\)

Diện tích tam giác:

\(S=\sqrt{24. \left(\right. 24 - 10 \left.\right) . \left(\right. 24 - 17 \left.\right) . \left(\right. 24 - 21 \left.\right)}=84\left(\right.cm^2\left.\right)\)

Nửa chu vi tam giác:

\(\frac{\left(\right. 10 + 17 + 21 \left.\right)}{2}=24\left(\operatorname{cm}\right.\left.\right)\)

Diện tích tam giác:

\(S=\sqrt{24. \left(\right. 24 - 10 \left.\right) . \left(\right. 24 - 17 \left.\right) . \left(\right. 24 - 21 \left.\right)}=84\left(\right.cm^2\left.\right)\)